diff --git a/src/accounting/static/js/account-selector.js b/src/accounting/static/js/account-selector.js
index 62096d9..c81458f 100644
--- a/src/accounting/static/js/account-selector.js
+++ b/src/accounting/static/js/account-selector.js
@@ -35,10 +35,10 @@ class AccountSelector {
     #lineItemEditor;
 
     /**
-     * The side, either "debit" or "credit"
+     * Either "debit" or "credit"
      * @type {string}
      */
-    #side;
+    #debitCredit;
 
     /**
      * The prefix of the HTML ID and class
@@ -86,12 +86,12 @@ class AccountSelector {
      * Constructs an account selector.
      *
      * @param lineItemEditor {VoucherLineItemEditor} the line item editor
-     * @param side {string} the side, either "debit" or "credit"
+     * @param debitCredit {string} either "debit" or "credit"
      */
-    constructor(lineItemEditor, side) {
+    constructor(lineItemEditor, debitCredit) {
         this.#lineItemEditor = lineItemEditor
-        this.#side = side;
-        this.#prefix = "accounting-account-selector-" + side;
+        this.#debitCredit = debitCredit;
+        this.#prefix = "accounting-account-selector-" + debitCredit;
         this.#query = document.getElementById(this.#prefix + "-query");
         this.#queryNoResult = document.getElementById(this.#prefix + "-option-no-result");
         this.#optionList = document.getElementById(this.#prefix + "-option-list");
@@ -143,7 +143,7 @@ class AccountSelector {
      * @return {string[]} the account codes that are used in the form
      */
     #getCodesUsedInForm() {
-        const inUse = this.#lineItemEditor.form.getAccountCodesUsed(this.#side);
+        const inUse = this.#lineItemEditor.form.getAccountCodesUsed(this.#debitCredit);
         if (this.#lineItemEditor.accountCode !== null) {
             inUse.push(this.#lineItemEditor.accountCode);
         }
@@ -217,7 +217,7 @@ class AccountSelector {
         const selectors = {}
         const modals = Array.from(document.getElementsByClassName("accounting-account-selector"));
         for (const modal of modals) {
-            selectors[modal.dataset.side] = new AccountSelector(lineItemEditor, modal.dataset.side);
+            selectors[modal.dataset.debitCredit] = new AccountSelector(lineItemEditor, modal.dataset.debitCredit);
         }
         return selectors;
     }
diff --git a/src/accounting/static/js/description-editor.js b/src/accounting/static/js/description-editor.js
index 6906eff..26c2c89 100644
--- a/src/accounting/static/js/description-editor.js
+++ b/src/accounting/static/js/description-editor.js
@@ -53,10 +53,10 @@ class DescriptionEditor {
     #modal;
 
     /**
-     * The side, either "debit" or "credit"
+     * Either "debit" or "credit"
      * @type {string}
      */
-    side;
+    debitCredit;
 
     /**
      * The current tab
@@ -110,12 +110,12 @@ class DescriptionEditor {
      * Constructs a description editor.
      *
      * @param lineItemEditor {VoucherLineItemEditor} the line item editor
-     * @param side {string} the side, either "debit" or "credit"
+     * @param debitCredit {string} either "debit" or "credit"
      */
-    constructor(lineItemEditor, side) {
+    constructor(lineItemEditor, debitCredit) {
         this.#lineItemEditor = lineItemEditor;
-        this.side = side;
-        this.prefix = "accounting-description-editor-" + side;
+        this.debitCredit = debitCredit;
+        this.prefix = "accounting-description-editor-" + debitCredit;
         this.#form = document.getElementById(this.prefix);
         this.#modal = document.getElementById(this.prefix + "-modal");
         this.description = document.getElementById(this.prefix + "-description");
@@ -253,7 +253,7 @@ class DescriptionEditor {
         const editors = {}
         const forms = Array.from(document.getElementsByClassName("accounting-description-editor"));
         for (const form of forms) {
-            editors[form.dataset.side] = new DescriptionEditor(lineItemEditor, form.dataset.side);
+            editors[form.dataset.debitCredit] = new DescriptionEditor(lineItemEditor, form.dataset.debitCredit);
         }
         return editors;
     }
diff --git a/src/accounting/static/js/original-line-item-selector.js b/src/accounting/static/js/original-line-item-selector.js
index 7d2b506..46cbfc4 100644
--- a/src/accounting/static/js/original-line-item-selector.js
+++ b/src/accounting/static/js/original-line-item-selector.js
@@ -77,9 +77,9 @@ class OriginalLineItemSelector {
     #currencyCode;
 
     /**
-     * The side, either "credit" or "debit"
+     * Either "credit" or "debit"
      */
-    #side;
+    #debitCredit;
 
     /**
      * Constructs an original line item selector.
@@ -157,7 +157,7 @@ class OriginalLineItemSelector {
     #filterOptions() {
         let hasAnyMatched = false;
         for (const option of this.#options) {
-            if (option.isMatched(this.#side, this.#currencyCode, this.#query.value)) {
+            if (option.isMatched(this.#debitCredit, this.#currencyCode, this.#query.value)) {
                 option.setShown(true);
                 hasAnyMatched = true;
             } else {
@@ -179,7 +179,7 @@ class OriginalLineItemSelector {
      */
     onOpen() {
         this.#currencyCode = this.lineItemEditor.getCurrencyCode();
-        this.#side = this.lineItemEditor.side;
+        this.#debitCredit = this.lineItemEditor.debitCredit;
         for (const option of this.#options) {
             option.setActive(option.id === this.lineItemEditor.originalLineItemId);
         }
@@ -220,10 +220,10 @@ class OriginalLineItem {
     date;
 
     /**
-     * The side, either "debit" or "credit"
+     * Either "debit" or "credit"
      * @type {string}
      */
-    #side;
+    #debitCredit;
 
     /**
      * The currency code
@@ -290,7 +290,7 @@ class OriginalLineItem {
         this.#element = element;
         this.id = element.dataset.id;
         this.date = element.dataset.date;
-        this.#side = element.dataset.side;
+        this.#debitCredit = element.dataset.debitCredit;
         this.#currencyCode = element.dataset.currencyCode;
         this.accountCode = element.dataset.accountCode;
         this.accountText = element.dataset.accountText;
@@ -335,27 +335,27 @@ class OriginalLineItem {
     /**
      * Returns whether the original matches.
      *
-     * @param side {string} the side, either "debit" or "credit"
+     * @param debitCredit {string} either "debit" or "credit"
      * @param currencyCode {string} the currency code
      * @param query {string|null} the query term
      */
-    isMatched(side, currencyCode, query = null) {
+    isMatched(debitCredit, currencyCode, query = null) {
         return this.netBalance.greaterThan(0)
             && this.date <= this.#selector.lineItemEditor.form.getDate()
-            && this.#isSideMatches(side)
+            && this.#isDebitCreditMatches(debitCredit)
             && this.#currencyCode === currencyCode
             && this.#isQueryMatches(query);
     }
 
     /**
-     * Returns whether the original line item matches the debit or credit side.
+     * Returns whether the original line item matches the debit or credit.
      *
-     * @param side {string} the side, either "debit" or credit
+     * @param debitCredit {string} either "debit" or credit
      * @return {boolean} true if the option matches, or false otherwise
      */
-    #isSideMatches(side) {
-        return (side === "debit" && this.#side === "credit")
-            || (side === "credit" && this.#side === "debit");
+    #isDebitCreditMatches(debitCredit) {
+        return (debitCredit === "debit" && this.#debitCredit === "credit")
+            || (debitCredit === "credit" && this.#debitCredit === "debit");
     }
 
     /**
diff --git a/src/accounting/static/js/voucher-form.js b/src/accounting/static/js/voucher-form.js
index 39d3036..5f7cc93 100644
--- a/src/accounting/static/js/voucher-form.js
+++ b/src/accounting/static/js/voucher-form.js
@@ -195,13 +195,13 @@ class VoucherForm {
     /**
      * Returns all the line items in the form.
      *
-     * @param side {string|null} the side, either "debit" or "credit", or null for both
+     * @param debitCredit {string|null} Either "debit" or "credit", or null for both
      * @return {LineItemSubForm[]} all the line item sub-forms
      */
-    getLineItems(side = null) {
+    getLineItems(debitCredit = null) {
         const lineItems = [];
         for (const currency of this.#currencies) {
-            lineItems.push(...currency.getLineItems(side));
+            lineItems.push(...currency.getLineItems(debitCredit));
         }
         return lineItems;
     }
@@ -209,11 +209,11 @@ class VoucherForm {
     /**
      * Returns the account codes used in the form.
      *
-     * @param side {string} the side, either "debit" or "credit"
+     * @param debitCredit {string} either "debit" or "credit"
      * @return {string[]} the account codes used in the form
      */
-    getAccountCodesUsed(side) {
-        return this.getLineItems(side).map((lineItem) => lineItem.getAccountCode())
+    getAccountCodesUsed(debitCredit) {
+        return this.getLineItems(debitCredit).map((lineItem) => lineItem.getAccountCode())
             .filter((code) => code !== null);
     }
 
@@ -406,14 +406,14 @@ class CurrencySubForm {
     deleteButton;
 
     /**
-     * The debit side
-     * @type {SideSubForm|null}
+     * The debit sub-form
+     * @type {DebitCreditSubForm|null}
      */
     #debit;
 
     /**
-     * The credit side
-     * @type {SideSubForm|null}
+     * The credit sub-form
+     * @type {DebitCreditSubForm|null}
      */
     #credit;
 
@@ -435,9 +435,9 @@ class CurrencySubForm {
         this.#codeSelect = document.getElementById(this.#prefix + "-code-select");
         this.deleteButton = document.getElementById(this.#prefix + "-delete");
         const debitElement = document.getElementById(this.#prefix + "-debit");
-        this.#debit = debitElement === null? null: new SideSubForm(this, debitElement, "debit");
+        this.#debit = debitElement === null? null: new DebitCreditSubForm(this, debitElement, "debit");
         const creditElement = document.getElementById(this.#prefix + "-credit");
-        this.#credit = creditElement == null? null: new SideSubForm(this, creditElement, "credit");
+        this.#credit = creditElement == null? null: new DebitCreditSubForm(this, creditElement, "credit");
         this.#codeSelect.onchange = () => this.#code.value = this.#codeSelect.value;
         this.deleteButton.onclick = () => {
             this.element.parentElement.removeChild(this.element);
@@ -457,15 +457,15 @@ class CurrencySubForm {
     /**
      * Returns all the line items in the form.
      *
-     * @param side {string|null} the side, either "debit" or "credit", or null for both
+     * @param debitCredit {string|null} either "debit" or "credit", or null for both
      * @return {LineItemSubForm[]} all the line item sub-forms
      */
-    getLineItems(side = null) {
+    getLineItems(debitCredit = null) {
         const lineItems = []
-        for (const sideSubForm of [this.#debit, this.#credit]) {
-            if (sideSubForm !== null ) {
-                if (side === null || sideSubForm.side === side) {
-                    lineItems.push(...sideSubForm.lineItems);
+        for (const debitCreditSubForm of [this.#debit, this.#credit]) {
+            if (debitCreditSubForm !== null ) {
+                if (debitCredit === null || debitCreditSubForm.debitCredit === debitCredit) {
+                    lineItems.push(...debitCreditSubForm.lineItems);
                 }
             }
         }
@@ -524,10 +524,10 @@ class CurrencySubForm {
 }
 
 /**
- * The debit or credit side sub-form
+ * The debit or credit sub-form
  *
  */
-class SideSubForm {
+class DebitCreditSubForm {
 
     /**
      * The currency sub-form
@@ -548,10 +548,10 @@ class SideSubForm {
     #currencyIndex;
 
     /**
-     * The side, either "debit" or "credit"
+     * Either "debit" or "credit"
      * @type {string}
      */
-    side;
+    debitCredit;
 
     /**
      * The prefix of the HTML ID and class
@@ -590,18 +590,18 @@ class SideSubForm {
     #addLineItemButton;
 
     /**
-     * Constructs a debit or credit side sub-form
+     * Constructs a debit or credit sub-form
      *
      * @param currency {CurrencySubForm} the currency sub-form
      * @param element {HTMLDivElement} the element
-     * @param side {string} the side, either "debit" or "credit"
+     * @param debitCredit {string} either "debit" or "credit"
      */
-    constructor(currency, element, side) {
+    constructor(currency, element, debitCredit) {
         this.currency = currency;
         this.#element = element;
         this.#currencyIndex = currency.index;
-        this.side = side;
-        this.#prefix = "accounting-currency-" + String(this.#currencyIndex) + "-" + side;
+        this.debitCredit = debitCredit;
+        this.#prefix = "accounting-currency-" + String(this.#currencyIndex) + "-" + debitCredit;
         this.#error = document.getElementById(this.#prefix + "-error");
         this.#lineItemList = document.getElementById(this.#prefix + "-list");
         // noinspection JSValidateTypes
@@ -622,7 +622,7 @@ class SideSubForm {
         const newIndex = 1 + (this.lineItems.length === 0? 0: Math.max(...this.lineItems.map((lineItem) => lineItem.lineItemIndex)));
         const html = this.currency.form.lineItemTemplate
             .replaceAll("CURRENCY_INDEX", escapeHtml(String(this.#currencyIndex)))
-            .replaceAll("SIDE", escapeHtml(this.side))
+            .replaceAll("DEBIT_CREDIT", escapeHtml(this.debitCredit))
             .replaceAll("LINE_ITEM_INDEX", escapeHtml(String(newIndex)));
         this.#lineItemList.insertAdjacentHTML("beforeend", html);
         const lineItem = new LineItemSubForm(this, document.getElementById(this.#prefix + "-" + String(newIndex)));
@@ -742,10 +742,10 @@ class SideSubForm {
 class LineItemSubForm {
 
     /**
-     * The debit or credit side sub-form
-     * @type {SideSubForm}
+     * The debit or credit sub-form
+     * @type {DebitCreditSubForm}
      */
-    sideSubForm;
+    debitCreditSubForm;
 
     /**
      * The element
@@ -754,10 +754,10 @@ class LineItemSubForm {
     element;
 
     /**
-     * The side, either "debit" or "credit"
+     * Either "debit" or "credit"
      * @type {string}
      */
-    side;
+    debitCredit;
 
     /**
      * The line item index
@@ -858,16 +858,16 @@ class LineItemSubForm {
     /**
      * Constructs the line item sub-form.
      *
-     * @param side {SideSubForm} the debit or credit side sub-form
+     * @param debitCredit {DebitCreditSubForm} the debit or credit sub-form
      * @param element {HTMLLIElement} the element
      */
-    constructor(side, element) {
-        this.sideSubForm = side;
+    constructor(debitCredit, element) {
+        this.debitCreditSubForm = debitCredit;
         this.element = element;
-        this.side = element.dataset.side;
+        this.debitCredit = element.dataset.debitCredit;
         this.lineItemIndex = parseInt(element.dataset.lineItemIndex);
         this.isMatched = element.classList.contains("accounting-matched-line-item");
-        this.#prefix = "accounting-currency-" + element.dataset.currencyIndex + "-" + this.side + "-" + this.lineItemIndex;
+        this.#prefix = "accounting-currency-" + element.dataset.currencyIndex + "-" + this.debitCredit + "-" + this.lineItemIndex;
         this.#control = document.getElementById(this.#prefix + "-control");
         this.#error = document.getElementById(this.#prefix + "-error");
         this.no = document.getElementById(this.#prefix + "-no");
@@ -881,10 +881,10 @@ class LineItemSubForm {
         this.#amount = document.getElementById(this.#prefix + "-amount");
         this.#amountText = document.getElementById(this.#prefix + "-amount-text");
         this.deleteButton = document.getElementById(this.#prefix + "-delete");
-        this.#control.onclick = () => this.sideSubForm.currency.form.lineItemEditor.onEdit(this);
+        this.#control.onclick = () => this.debitCreditSubForm.currency.form.lineItemEditor.onEdit(this);
         this.deleteButton.onclick = () => {
             this.element.parentElement.removeChild(this.element);
-            this.sideSubForm.deleteLineItem(this);
+            this.debitCreditSubForm.deleteLineItem(this);
         };
     }
 
@@ -1019,9 +1019,9 @@ class LineItemSubForm {
         this.#amount.value = editor.amount;
         this.#amountText.innerText = formatDecimal(new Decimal(editor.amount));
         this.validate();
-        this.sideSubForm.updateTotal();
-        this.sideSubForm.currency.updateCodeSelectorStatus();
-        this.sideSubForm.currency.form.updateMinDate();
+        this.debitCreditSubForm.updateTotal();
+        this.debitCreditSubForm.currency.updateCodeSelectorStatus();
+        this.debitCreditSubForm.currency.form.updateMinDate();
     }
 }
 
diff --git a/src/accounting/static/js/voucher-line-item-editor.js b/src/accounting/static/js/voucher-line-item-editor.js
index cb74ae3..408004d 100644
--- a/src/accounting/static/js/voucher-line-item-editor.js
+++ b/src/accounting/static/js/voucher-line-item-editor.js
@@ -47,10 +47,10 @@ class VoucherLineItemEditor {
     #modal;
 
     /**
-     * The side, either "debit" or "credit"
+     * Either "debit" or "credit"
      * @type {string}
      */
-    side;
+    debitCredit;
 
     /**
      * The prefix of the HTML ID and class
@@ -143,10 +143,10 @@ class VoucherLineItemEditor {
     lineItem;
 
     /**
-     * The debit or credit side sub-form
-     * @type {SideSubForm}
+     * The debit or credit sub-form
+     * @type {DebitCreditSubForm}
      */
-    #sideSubForm;
+    #debitCreditSubForm;
 
     /**
      * Whether the voucher line item needs offset
@@ -241,13 +241,13 @@ class VoucherLineItemEditor {
         this.originalLineItemSelector = new OriginalLineItemSelector(this);
         this.#originalLineItemControl.onclick = () => this.originalLineItemSelector.onOpen()
         this.#originalLineItemDelete.onclick = () => this.clearOriginalLineItem();
-        this.#descriptionControl.onclick = () => this.#descriptionEditors[this.side].onOpen();
-        this.#accountControl.onclick = () => this.#accountSelectors[this.side].onOpen();
+        this.#descriptionControl.onclick = () => this.#descriptionEditors[this.debitCredit].onOpen();
+        this.#accountControl.onclick = () => this.#accountSelectors[this.debitCredit].onOpen();
         this.#amountInput.onchange = () => this.#validateAmount();
         this.#element.onsubmit = () => {
             if (this.#validate()) {
                 if (this.lineItem === null) {
-                    this.lineItem = this.#sideSubForm.addLineItem();
+                    this.lineItem = this.#debitCreditSubForm.addLineItem();
                 }
                 this.amount = this.#amountInput.value;
                 this.lineItem.save(this);
@@ -314,7 +314,7 @@ class VoucherLineItemEditor {
      * @return {string} the currency code
      */
     getCurrencyCode() {
-        return this.#sideSubForm.currency.getCurrencyCode();
+        return this.#debitCreditSubForm.currency.getCurrencyCode();
     }
 
     /**
@@ -478,12 +478,12 @@ class VoucherLineItemEditor {
     /**
      * The callback when adding a new voucher line item.
      *
-     * @param side {SideSubForm} the debit or credit side sub-form
+     * @param debitCredit {DebitCreditSubForm} the debit or credit sub-form
      */
-    onAddNew(side) {
+    onAddNew(debitCredit) {
         this.lineItem = null;
-        this.#sideSubForm = side;
-        this.side = this.#sideSubForm.side;
+        this.#debitCreditSubForm = debitCredit;
+        this.debitCredit = this.#debitCreditSubForm.debitCredit;
         this.isNeedOffset = false;
         this.#originalLineItemContainer.classList.add("d-none");
         this.#originalLineItemControl.classList.remove("accounting-not-empty");
@@ -518,8 +518,8 @@ class VoucherLineItemEditor {
      */
     onEdit(lineItem) {
         this.lineItem = lineItem;
-        this.#sideSubForm = lineItem.sideSubForm;
-        this.side = this.#sideSubForm.side;
+        this.#debitCreditSubForm = lineItem.debitCreditSubForm;
+        this.debitCredit = this.#debitCreditSubForm.debitCredit;
         this.isNeedOffset = lineItem.isNeedOffset();
         this.originalLineItemId = lineItem.getOriginalLineItemId();
         this.originalLineItemDate = lineItem.getOriginalLineItemDate();
@@ -575,11 +575,11 @@ class VoucherLineItemEditor {
     #setEnableDescriptionAccount(isEnabled) {
         if (isEnabled) {
             this.#descriptionControl.dataset.bsToggle = "modal";
-            this.#descriptionControl.dataset.bsTarget = "#accounting-description-editor-" + this.#sideSubForm.side + "-modal";
+            this.#descriptionControl.dataset.bsTarget = "#accounting-description-editor-" + this.#debitCreditSubForm.debitCredit + "-modal";
             this.#descriptionControl.classList.remove("accounting-disabled");
             this.#descriptionControl.classList.add("accounting-clickable");
             this.#accountControl.dataset.bsToggle = "modal";
-            this.#accountControl.dataset.bsTarget = "#accounting-account-selector-" + this.#sideSubForm.side + "-modal";
+            this.#accountControl.dataset.bsTarget = "#accounting-account-selector-" + this.#debitCreditSubForm.debitCredit + "-modal";
             this.#accountControl.classList.remove("accounting-disabled");
             this.#accountControl.classList.add("accounting-clickable");
         } else {
diff --git a/src/accounting/templates/accounting/voucher/disbursement/include/form-currency-item.html b/src/accounting/templates/accounting/voucher/disbursement/include/form-currency-item.html
index 2cc9847..d7ec6e4 100644
--- a/src/accounting/templates/accounting/voucher/disbursement/include/form-currency-item.html
+++ b/src/accounting/templates/accounting/voucher/disbursement/include/form-currency-item.html
@@ -47,7 +47,7 @@ First written: 2023/2/25
         <ul id="accounting-currency-{{ currency_index }}-debit-list" class="list-group accounting-line-item-list">
           {% for line_item_form in debit_forms %}
             {% with currency_index = currency_index,
-                    side = "debit",
+                    debit_credit = "debit",
                     line_item_index = loop.index,
                     only_one_line_item_form = debit_forms|length == 1,
                     form = line_item_form.form %}
@@ -62,7 +62,7 @@ First written: 2023/2/25
         </div>
 
         <div>
-          <button id="accounting-currency-{{ currency_index }}-debit-add-line-item" class="btn btn-primary" type="button" data-currency-index="{{ currency_index }}" data-side="debit" data-bs-toggle="modal" data-bs-target="#accounting-line-item-editor-modal">
+          <button id="accounting-currency-{{ currency_index }}-debit-add-line-item" class="btn btn-primary" type="button" data-currency-index="{{ currency_index }}" data-debit-credit="debit" data-bs-toggle="modal" data-bs-target="#accounting-line-item-editor-modal">
             <i class="fas fa-plus"></i>
             {{ A_("New") }}
           </button>
diff --git a/src/accounting/templates/accounting/voucher/disbursement/include/form.html b/src/accounting/templates/accounting/voucher/disbursement/include/form.html
index b47e3bd..eabea46 100644
--- a/src/accounting/templates/accounting/voucher/disbursement/include/form.html
+++ b/src/accounting/templates/accounting/voucher/disbursement/include/form.html
@@ -50,7 +50,7 @@ First written: 2023/2/25
   {% with description_editor = form.description_editor.debit %}
     {% include "accounting/voucher/include/description-editor-modal.html" %}
   {% endwith %}
-  {% with side = "debit",
+  {% with debit_credit = "debit",
           account_options = form.debit_account_options %}
     {% include "accounting/voucher/include/account-selector-modal.html" %}
   {% endwith %}
diff --git a/src/accounting/templates/accounting/voucher/include/account-selector-modal.html b/src/accounting/templates/accounting/voucher/include/account-selector-modal.html
index f223311..ee2fd10 100644
--- a/src/accounting/templates/accounting/voucher/include/account-selector-modal.html
+++ b/src/accounting/templates/accounting/voucher/include/account-selector-modal.html
@@ -19,35 +19,35 @@ account-selector-modal.html: The modal for the account selector
 Author: imacat@mail.imacat.idv.tw (imacat)
 First written: 2023/2/25
 #}
-<div id="accounting-account-selector-{{ side }}-modal" class="modal fade accounting-account-selector" data-side="{{ side }}" tabindex="-1" aria-labelledby="accounting-account-selector-{{ side }}-modal-label" aria-hidden="true">
+<div id="accounting-account-selector-{{ debit_credit }}-modal" class="modal fade accounting-account-selector" data-debit-credit="{{ debit_credit }}" tabindex="-1" aria-labelledby="accounting-account-selector-{{ debit_credit }}-modal-label" aria-hidden="true">
   <div class="modal-dialog">
     <div class="modal-content">
       <div class="modal-header">
-        <h1 class="modal-title fs-5" id="accounting-account-selector-{{ side }}-modal-label">{{ A_("Select Account") }}</h1>
+        <h1 class="modal-title fs-5" id="accounting-account-selector-{{ debit_credit }}-modal-label">{{ A_("Select Account") }}</h1>
         <button type="button" class="btn-close" data-bs-toggle="modal" data-bs-target="#accounting-line-item-editor-modal" aria-label="{{ A_("Close") }}"></button>
       </div>
       <div class="modal-body">
         <div class="input-group mb-2">
-          <input id="accounting-account-selector-{{ side }}-query" class="form-control form-control-sm" type="search" placeholder=" " required="required">
-          <label class="input-group-text" for="accounting-account-selector-{{ side }}-query">
+          <input id="accounting-account-selector-{{ debit_credit }}-query" class="form-control form-control-sm" type="search" placeholder=" " required="required">
+          <label class="input-group-text" for="accounting-account-selector-{{ debit_credit }}-query">
             <i class="fa-solid fa-magnifying-glass"></i>
             {{ A_("Search") }}
           </label>
         </div>
 
-        <ul id="accounting-account-selector-{{ side }}-option-list" class="list-group accounting-selector-list">
+        <ul id="accounting-account-selector-{{ debit_credit }}-option-list" class="list-group accounting-selector-list">
           {% for account in account_options %}
-            <li id="accounting-account-selector-{{ side }}-option-{{ account.code }}" class="list-group-item accounting-clickable accounting-account-selector-{{ side }}-option {% if account.is_in_use %} accounting-account-in-use {% endif %} {% if account.is_need_offset %} accounting-account-is-need-offset {% endif %}" data-code="{{ account.code }}" data-content="{{ account }}" data-query-values="{{ account.query_values|tojson|forceescape }}" data-bs-toggle="modal" data-bs-target="#accounting-line-item-editor-modal">
+            <li id="accounting-account-selector-{{ debit_credit }}-option-{{ account.code }}" class="list-group-item accounting-clickable accounting-account-selector-{{ debit_credit }}-option {% if account.is_in_use %} accounting-account-in-use {% endif %} {% if account.is_need_offset %} accounting-account-is-need-offset {% endif %}" data-code="{{ account.code }}" data-content="{{ account }}" data-query-values="{{ account.query_values|tojson|forceescape }}" data-bs-toggle="modal" data-bs-target="#accounting-line-item-editor-modal">
               {{ account }}
             </li>
           {% endfor %}
-          <li id="accounting-account-selector-{{ side }}-more" class="list-group-item accounting-clickable">{{ A_("More…") }}</li>
+          <li id="accounting-account-selector-{{ debit_credit }}-more" class="list-group-item accounting-clickable">{{ A_("More…") }}</li>
         </ul>
-        <p id="accounting-account-selector-{{ side }}-option-no-result" class="d-none">{{ A_("There is no data.") }}</p>
+        <p id="accounting-account-selector-{{ debit_credit }}-option-no-result" class="d-none">{{ A_("There is no data.") }}</p>
       </div>
       <div class="modal-footer">
         <button type="button" class="btn btn-secondary" data-bs-toggle="modal" data-bs-target="#accounting-line-item-editor-modal">{{ A_("Cancel") }}</button>
-        <button id="accounting-account-selector-{{ side }}-btn-clear" type="button" class="btn btn-danger" data-bs-toggle="modal" data-bs-target="#accounting-line-item-editor-modal">{{ A_("Clear") }}</button>
+        <button id="accounting-account-selector-{{ debit_credit }}-btn-clear" type="button" class="btn btn-danger" data-bs-toggle="modal" data-bs-target="#accounting-line-item-editor-modal">{{ A_("Clear") }}</button>
       </div>
     </div>
   </div>
diff --git a/src/accounting/templates/accounting/voucher/include/description-editor-modal.html b/src/accounting/templates/accounting/voucher/include/description-editor-modal.html
index 3e06f78..da36eb0 100644
--- a/src/accounting/templates/accounting/voucher/include/description-editor-modal.html
+++ b/src/accounting/templates/accounting/voucher/include/description-editor-modal.html
@@ -19,20 +19,20 @@ description-editor-modal.html: The modal of the description editor
 Author: imacat@mail.imacat.idv.tw (imacat)
 First written: 2023/2/28
 #}
-<form id="accounting-description-editor-{{ description_editor.side }}" class="accounting-description-editor" data-side="{{ description_editor.side }}">
-  <div id="accounting-description-editor-{{ description_editor.side }}-modal" class="modal fade" tabindex="-1" aria-labelledby="accounting-description-editor-{{ description_editor.side }}-modal-label" aria-hidden="true">
+<form id="accounting-description-editor-{{ description_editor.debit_credit }}" class="accounting-description-editor" data-debit-credit="{{ description_editor.debit_credit }}">
+  <div id="accounting-description-editor-{{ description_editor.debit_credit }}-modal" class="modal fade" tabindex="-1" aria-labelledby="accounting-description-editor-{{ description_editor.debit_credit }}-modal-label" aria-hidden="true">
     <div class="modal-dialog">
       <div class="modal-content">
         <div class="modal-header">
-          <h1 class="modal-title fs-5" id="accounting-description-editor-{{ description_editor.side }}-modal-label">
-            <label for="accounting-description-editor-{{ description_editor.side }}-description">{{ A_("Description") }}</label>
+          <h1 class="modal-title fs-5" id="accounting-description-editor-{{ description_editor.debit_credit }}-modal-label">
+            <label for="accounting-description-editor-{{ description_editor.debit_credit }}-description">{{ A_("Description") }}</label>
           </h1>
           <button class="btn-close" type="button" data-bs-toggle="modal" data-bs-target="#accounting-line-item-editor-modal" aria-label="{{ A_("Close") }}"></button>
         </div>
         <div class="modal-body">
           <div class="d-flex justify-content-between mb-3">
-            <input id="accounting-description-editor-{{ description_editor.side }}-description" class="form-control" type="text" aria-labelledby="accounting-description-editor-{{ description_editor.side }}-modal-label">
-            <button id="accounting-description-editor-{{ description_editor.side }}-offset" class="btn btn-primary text-nowrap ms-2" type="button" data-bs-toggle="modal" data-bs-target="#accounting-original-line-item-selector-modal">
+            <input id="accounting-description-editor-{{ description_editor.debit_credit }}-description" class="form-control" type="text" aria-labelledby="accounting-description-editor-{{ description_editor.debit_credit }}-modal-label">
+            <button id="accounting-description-editor-{{ description_editor.debit_credit }}-offset" class="btn btn-primary text-nowrap ms-2" type="button" data-bs-toggle="modal" data-bs-target="#accounting-original-line-item-selector-modal">
               {{ A_("Offset...") }}
             </button>
           </div>
@@ -40,43 +40,43 @@ First written: 2023/2/28
           {# Tab navigation #}
           <ul class="nav nav-tabs mb-2">
             <li class="nav-item">
-              <span id="accounting-description-editor-{{ description_editor.side }}-general-tab" class="nav-link active accounting-clickable" aria-current="page">
+              <span id="accounting-description-editor-{{ description_editor.debit_credit }}-general-tab" class="nav-link active accounting-clickable" aria-current="page">
                 {{ A_("General") }}
               </span>
             </li>
             <li class="nav-item">
-              <span id="accounting-description-editor-{{ description_editor.side }}-travel-tab" class="nav-link accounting-clickable" aria-current="false">
+              <span id="accounting-description-editor-{{ description_editor.debit_credit }}-travel-tab" class="nav-link accounting-clickable" aria-current="false">
                 {{ A_("Travel") }}
               </span>
             </li>
             <li class="nav-item">
-              <span id="accounting-description-editor-{{ description_editor.side }}-bus-tab" class="nav-link accounting-clickable" aria-current="false">
+              <span id="accounting-description-editor-{{ description_editor.debit_credit }}-bus-tab" class="nav-link accounting-clickable" aria-current="false">
                 {{ A_("Bus") }}
               </span>
             </li>
             <li class="nav-item">
-              <span id="accounting-description-editor-{{ description_editor.side }}-regular-tab" class="nav-link accounting-clickable" aria-current="false">
+              <span id="accounting-description-editor-{{ description_editor.debit_credit }}-regular-tab" class="nav-link accounting-clickable" aria-current="false">
                 {{ A_("Regular") }}
               </span>
             </li>
             <li class="nav-item">
-              <span id="accounting-description-editor-{{ description_editor.side }}-annotation-tab" class="nav-link accounting-clickable" aria-current="false">
+              <span id="accounting-description-editor-{{ description_editor.debit_credit }}-annotation-tab" class="nav-link accounting-clickable" aria-current="false">
                 {{ A_("Annotation") }}
               </span>
             </li>
           </ul>
 
           {# A general description with a tag #}
-          <div id="accounting-description-editor-{{ description_editor.side }}-general-page" aria-current="page" aria-labelledby="accounting-description-editor-{{ description_editor.side }}-general-tab">
+          <div id="accounting-description-editor-{{ description_editor.debit_credit }}-general-page" aria-current="page" aria-labelledby="accounting-description-editor-{{ description_editor.debit_credit }}-general-tab">
             <div class="form-floating mb-2">
-              <input id="accounting-description-editor-{{ description_editor.side }}-general-tag" class="form-control" type="text" value="" placeholder=" ">
-              <label class="form-label" for="accounting-description-editor-{{ description_editor.side }}-general-tag">{{ A_("Tag") }}</label>
-              <div id="accounting-description-editor-{{ description_editor.side }}-general-tag-error" class="invalid-feedback"></div>
+              <input id="accounting-description-editor-{{ description_editor.debit_credit }}-general-tag" class="form-control" type="text" value="" placeholder=" ">
+              <label class="form-label" for="accounting-description-editor-{{ description_editor.debit_credit }}-general-tag">{{ A_("Tag") }}</label>
+              <div id="accounting-description-editor-{{ description_editor.debit_credit }}-general-tag-error" class="invalid-feedback"></div>
             </div>
 
             <div>
               {% for tag in description_editor.general.tags %}
-                <button class="btn btn-outline-primary accounting-description-editor-{{ description_editor.side }}-general-btn-tag" type="button" tabindex="-1" data-value="{{ tag.name }}" data-accounts="{{ tag.account_codes|tojson|forceescape }}">
+                <button class="btn btn-outline-primary accounting-description-editor-{{ description_editor.debit_credit }}-general-btn-tag" type="button" tabindex="-1" data-value="{{ tag.name }}" data-accounts="{{ tag.account_codes|tojson|forceescape }}">
                   {{ tag }}
                 </button>
               {% endfor %}
@@ -84,16 +84,16 @@ First written: 2023/2/28
           </div>
 
           {# A general trip with the origin and distination #}
-          <div id="accounting-description-editor-{{ description_editor.side }}-travel-page" class="d-none" aria-current="false" aria-labelledby="accounting-description-editor-{{ description_editor.side }}-travel-tab">
+          <div id="accounting-description-editor-{{ description_editor.debit_credit }}-travel-page" class="d-none" aria-current="false" aria-labelledby="accounting-description-editor-{{ description_editor.debit_credit }}-travel-tab">
             <div class="form-floating mb-2">
-              <input id="accounting-description-editor-{{ description_editor.side }}-travel-tag" class="form-control" type="text" value="" placeholder=" ">
-              <label class="form-label" for="accounting-description-editor-{{ description_editor.side }}-travel-tag">{{ A_("Tag") }}</label>
-              <div id="accounting-description-editor-{{ description_editor.side }}-travel-tag-error" class="invalid-feedback"></div>
+              <input id="accounting-description-editor-{{ description_editor.debit_credit }}-travel-tag" class="form-control" type="text" value="" placeholder=" ">
+              <label class="form-label" for="accounting-description-editor-{{ description_editor.debit_credit }}-travel-tag">{{ A_("Tag") }}</label>
+              <div id="accounting-description-editor-{{ description_editor.debit_credit }}-travel-tag-error" class="invalid-feedback"></div>
             </div>
 
             <div>
               {% for tag in description_editor.travel.tags %}
-                <button class="btn btn-outline-primary accounting-description-editor-{{ description_editor.side }}-travel-btn-tag" type="button" tabindex="-1" data-value="{{ tag.name }}" data-accounts="{{ tag.account_codes|tojson|forceescape }}">
+                <button class="btn btn-outline-primary accounting-description-editor-{{ description_editor.debit_credit }}-travel-btn-tag" type="button" tabindex="-1" data-value="{{ tag.name }}" data-accounts="{{ tag.account_codes|tojson|forceescape }}">
                   {{ tag }}
                 </button>
               {% endfor %}
@@ -101,40 +101,40 @@ First written: 2023/2/28
 
             <div class="d-flex justify-content-between mt-2">
               <div class="form-floating">
-                <input id="accounting-description-editor-{{ description_editor.side }}-travel-from" class="form-control" type="text" value="" placeholder=" ">
-                <label class="form-label" for="accounting-description-editor-{{ description_editor.side }}-travel-from">{{ A_("From") }}</label>
-                <div id="accounting-description-editor-{{ description_editor.side }}-travel-from-error" class="invalid-feedback"></div>
+                <input id="accounting-description-editor-{{ description_editor.debit_credit }}-travel-from" class="form-control" type="text" value="" placeholder=" ">
+                <label class="form-label" for="accounting-description-editor-{{ description_editor.debit_credit }}-travel-from">{{ A_("From") }}</label>
+                <div id="accounting-description-editor-{{ description_editor.debit_credit }}-travel-from-error" class="invalid-feedback"></div>
               </div>
               <div class="btn-group-vertical ms-1 me-1">
-                <button class="btn btn-primary accounting-description-editor-{{ description_editor.side }}-travel-direction accounting-default" type="button" tabindex="-1" data-arrow="&rarr;">&rarr;</button>
-                <button class="btn btn-outline-primary accounting-description-editor-{{ description_editor.side }}-travel-direction" type="button" tabindex="-1" data-arrow="&harr;">&harr;</button>
+                <button class="btn btn-primary accounting-description-editor-{{ description_editor.debit_credit }}-travel-direction accounting-default" type="button" tabindex="-1" data-arrow="&rarr;">&rarr;</button>
+                <button class="btn btn-outline-primary accounting-description-editor-{{ description_editor.debit_credit }}-travel-direction" type="button" tabindex="-1" data-arrow="&harr;">&harr;</button>
               </div>
               <div class="form-floating">
-                <input id="accounting-description-editor-{{ description_editor.side }}-travel-to" class="form-control" type="text" value="" placeholder=" ">
-                <label class="form-label" for="accounting-description-editor-{{ description_editor.side }}-travel-to">{{ A_("To") }}</label>
-                <div id="accounting-description-editor-{{ description_editor.side }}-travel-to-error" class="invalid-feedback"></div>
+                <input id="accounting-description-editor-{{ description_editor.debit_credit }}-travel-to" class="form-control" type="text" value="" placeholder=" ">
+                <label class="form-label" for="accounting-description-editor-{{ description_editor.debit_credit }}-travel-to">{{ A_("To") }}</label>
+                <div id="accounting-description-editor-{{ description_editor.debit_credit }}-travel-to-error" class="invalid-feedback"></div>
               </div>
             </div>
           </div>
 
           {# A bus trip with the route name or route number, the origin and distination #}
-          <div id="accounting-description-editor-{{ description_editor.side }}-bus-page" class="d-none" aria-current="false" aria-labelledby="accounting-description-editor-{{ description_editor.side }}-bus-tab">
+          <div id="accounting-description-editor-{{ description_editor.debit_credit }}-bus-page" class="d-none" aria-current="false" aria-labelledby="accounting-description-editor-{{ description_editor.debit_credit }}-bus-tab">
             <div class="d-flex justify-content-between mb-2">
               <div class="form-floating me-2">
-                <input id="accounting-description-editor-{{ description_editor.side }}-bus-tag" class="form-control" type="text" value="" placeholder=" ">
-                <label class="form-label" for="accounting-description-editor-{{ description_editor.side }}-bus-tag">{{ A_("Tag") }}</label>
-                <div id="accounting-description-editor-{{ description_editor.side }}-bus-tag-error" class="invalid-feedback"></div>
+                <input id="accounting-description-editor-{{ description_editor.debit_credit }}-bus-tag" class="form-control" type="text" value="" placeholder=" ">
+                <label class="form-label" for="accounting-description-editor-{{ description_editor.debit_credit }}-bus-tag">{{ A_("Tag") }}</label>
+                <div id="accounting-description-editor-{{ description_editor.debit_credit }}-bus-tag-error" class="invalid-feedback"></div>
               </div>
               <div class="form-floating">
-                <input id="accounting-description-editor-{{ description_editor.side }}-bus-route" class="form-control" type="text" value="" placeholder=" ">
-                <label class="form-label" for="accounting-description-editor-{{ description_editor.side }}-bus-route">{{ A_("Route") }}</label>
-                <div id="accounting-description-editor-{{ description_editor.side }}-bus-route-error" class="invalid-feedback"></div>
+                <input id="accounting-description-editor-{{ description_editor.debit_credit }}-bus-route" class="form-control" type="text" value="" placeholder=" ">
+                <label class="form-label" for="accounting-description-editor-{{ description_editor.debit_credit }}-bus-route">{{ A_("Route") }}</label>
+                <div id="accounting-description-editor-{{ description_editor.debit_credit }}-bus-route-error" class="invalid-feedback"></div>
               </div>
             </div>
 
             <div>
               {% for tag in description_editor.bus.tags %}
-                <button class="btn btn-outline-primary accounting-description-editor-{{ description_editor.side }}-bus-btn-tag" type="button" tabindex="-1" data-value="{{ tag.name }}" data-accounts="{{ tag.account_codes|tojson|forceescape }}">
+                <button class="btn btn-outline-primary accounting-description-editor-{{ description_editor.debit_credit }}-bus-btn-tag" type="button" tabindex="-1" data-value="{{ tag.name }}" data-accounts="{{ tag.account_codes|tojson|forceescape }}">
                   {{ tag }}
                 </button>
               {% endfor %}
@@ -142,42 +142,42 @@ First written: 2023/2/28
 
             <div class="d-flex justify-content-between mt-2">
               <div class="form-floating me-2">
-                <input id="accounting-description-editor-{{ description_editor.side }}-bus-from" class="form-control" type="text" value="" placeholder=" ">
-                <label class="form-label" for="accounting-description-editor-{{ description_editor.side }}-bus-from">{{ A_("From") }}</label>
-                <div id="accounting-description-editor-{{ description_editor.side }}-bus-from-error" class="invalid-feedback"></div>
+                <input id="accounting-description-editor-{{ description_editor.debit_credit }}-bus-from" class="form-control" type="text" value="" placeholder=" ">
+                <label class="form-label" for="accounting-description-editor-{{ description_editor.debit_credit }}-bus-from">{{ A_("From") }}</label>
+                <div id="accounting-description-editor-{{ description_editor.debit_credit }}-bus-from-error" class="invalid-feedback"></div>
               </div>
               <div class="form-floating">
-                <input id="accounting-description-editor-{{ description_editor.side }}-bus-to" class="form-control" type="text" value="" placeholder=" ">
-                <label class="form-label" for="accounting-description-editor-{{ description_editor.side }}-bus-to">{{ A_("To") }}</label>
-                <div id="accounting-description-editor-{{ description_editor.side }}-bus-to-error" class="invalid-feedback"></div>
+                <input id="accounting-description-editor-{{ description_editor.debit_credit }}-bus-to" class="form-control" type="text" value="" placeholder=" ">
+                <label class="form-label" for="accounting-description-editor-{{ description_editor.debit_credit }}-bus-to">{{ A_("To") }}</label>
+                <div id="accounting-description-editor-{{ description_editor.debit_credit }}-bus-to-error" class="invalid-feedback"></div>
               </div>
             </div>
           </div>
 
           {# A regular income or payment #}
-          <div id="accounting-description-editor-{{ description_editor.side }}-regular-page" class="d-none" aria-current="false" aria-labelledby="accounting-description-editor-{{ description_editor.side }}-regular-tab">
+          <div id="accounting-description-editor-{{ description_editor.debit_credit }}-regular-page" class="d-none" aria-current="false" aria-labelledby="accounting-description-editor-{{ description_editor.debit_credit }}-regular-tab">
             {# TODO: To be done #}
           </div>
 
           {# The annotation #}
-          <div id="accounting-description-editor-{{ description_editor.side }}-annotation-page" class="d-none" aria-current="false" aria-labelledby="accounting-description-editor-{{ description_editor.side }}-annotation-tab">
+          <div id="accounting-description-editor-{{ description_editor.debit_credit }}-annotation-page" class="d-none" aria-current="false" aria-labelledby="accounting-description-editor-{{ description_editor.debit_credit }}-annotation-tab">
             <div class="form-floating">
-              <input id="accounting-description-editor-{{ description_editor.side }}-annotation-number" class="form-control" type="number" min="1" value="" placeholder=" ">
-              <label class="form-label" for="accounting-description-editor-{{ description_editor.side }}-annotation-number">{{ A_("The number of items") }}</label>
-              <div id="accounting-description-editor-{{ description_editor.side }}-annotation-number-error" class="invalid-feedback"></div>
+              <input id="accounting-description-editor-{{ description_editor.debit_credit }}-annotation-number" class="form-control" type="number" min="1" value="" placeholder=" ">
+              <label class="form-label" for="accounting-description-editor-{{ description_editor.debit_credit }}-annotation-number">{{ A_("The number of items") }}</label>
+              <div id="accounting-description-editor-{{ description_editor.debit_credit }}-annotation-number-error" class="invalid-feedback"></div>
             </div>
 
             <div class="form-floating mt-2">
-              <input id="accounting-description-editor-{{ description_editor.side }}-annotation-note" class="form-control" type="text" value="" placeholder=" ">
-              <label class="form-label" for="accounting-description-editor-{{ description_editor.side }}-annotation-note">{{ A_("Note") }}</label>
-              <div id="accounting-description-editor-{{ description_editor.side }}-annotation-note-error" class="invalid-feedback"></div>
+              <input id="accounting-description-editor-{{ description_editor.debit_credit }}-annotation-note" class="form-control" type="text" value="" placeholder=" ">
+              <label class="form-label" for="accounting-description-editor-{{ description_editor.debit_credit }}-annotation-note">{{ A_("Note") }}</label>
+              <div id="accounting-description-editor-{{ description_editor.debit_credit }}-annotation-note-error" class="invalid-feedback"></div>
             </div>
           </div>
 
           {# The suggested accounts #}
           <div class="mt-3">
             {% for account in description_editor.accounts %}
-              <button class="btn btn-outline-primary d-none accounting-description-editor-{{ description_editor.side }}-account {% if account.is_need_offset %} accounting-account-is-need-offset {% endif %}" type="button" data-code="{{ account.code }}" data-text="{{ account }}">
+              <button class="btn btn-outline-primary d-none accounting-description-editor-{{ description_editor.debit_credit }}-account {% if account.is_need_offset %} accounting-account-is-need-offset {% endif %}" type="button" data-code="{{ account.code }}" data-text="{{ account }}">
                 {{ account }}
               </button>
             {% endfor %}
@@ -185,7 +185,7 @@ First written: 2023/2/28
         </div>
         <div class="modal-footer">
           <button class="btn btn-secondary" type="button" data-bs-toggle="modal" data-bs-target="#accounting-line-item-editor-modal">{{ A_("Cancel") }}</button>
-          <button id="accounting-description-editor-{{ description_editor.side }}-btn-save" type="submit" class="btn btn-primary">{{ A_("Save") }}</button>
+          <button id="accounting-description-editor-{{ description_editor.debit_credit }}-btn-save" type="submit" class="btn btn-primary">{{ A_("Save") }}</button>
         </div>
       </div>
     </div>
diff --git a/src/accounting/templates/accounting/voucher/include/form-line-item.html b/src/accounting/templates/accounting/voucher/include/form-line-item.html
index f331bab..3ab307b 100644
--- a/src/accounting/templates/accounting/voucher/include/form-line-item.html
+++ b/src/accounting/templates/accounting/voucher/include/form-line-item.html
@@ -20,24 +20,24 @@ Author: imacat@mail.imacat.idv.tw (imacat)
 First written: 2023/2/25
 #}
 {# <ul> For SonarQube not to complain about incorrect HTML #}
-<li id="accounting-currency-{{ currency_index }}-{{ side }}-{{ line_item_index }}" class="list-group-item list-group-item-action d-flex justify-content-between accounting-currency-{{ currency_index }}-{{ side }} {% if form.offsets %} accounting-matched-line-item {% endif %}" data-currency-index="{{ currency_index }}" data-side="{{ side }}" data-line-item-index="{{ line_item_index }}" {% if form.is_need_offset %} data-is-need-offset="true" {% endif %}>
+<li id="accounting-currency-{{ currency_index }}-{{ debit_credit }}-{{ line_item_index }}" class="list-group-item list-group-item-action d-flex justify-content-between accounting-currency-{{ currency_index }}-{{ debit_credit }} {% if form.offsets %} accounting-matched-line-item {% endif %}" data-currency-index="{{ currency_index }}" data-debit-credit="{{ debit_credit }}" data-line-item-index="{{ line_item_index }}" {% if form.is_need_offset %} data-is-need-offset="true" {% endif %}>
   {% if form.eid.data %}
-    <input type="hidden" name="currency-{{ currency_index }}-{{ side }}-{{ line_item_index }}-eid" value="{{ form.eid.data }}">
+    <input type="hidden" name="currency-{{ currency_index }}-{{ debit_credit }}-{{ line_item_index }}-eid" value="{{ form.eid.data }}">
   {% endif %}
-  <input id="accounting-currency-{{ currency_index }}-{{ side }}-{{ line_item_index }}-no" type="hidden" name="currency-{{ currency_index }}-{{ side }}-{{ line_item_index }}-no" value="{{ line_item_index }}">
-  <input id="accounting-currency-{{ currency_index }}-{{ side }}-{{ line_item_index }}-original-line-item-id" class="accounting-original-line-item-id" type="hidden" name="currency-{{ currency_index }}-{{ side }}-{{ line_item_index }}-original_line_item_id" value="{{ form.original_line_item_id.data|accounting_default }}" data-date="{{ form.original_line_item_date|accounting_default }}" data-text="{{ form.original_line_item_text|accounting_default }}">
-  <input id="accounting-currency-{{ currency_index }}-{{ side }}-{{ line_item_index }}-account-code" type="hidden" name="currency-{{ currency_index }}-{{ side }}-{{ line_item_index }}-account_code" value="{{ form.account_code.data|accounting_default }}" data-text="{{ form.account_text }}">
-  <input id="accounting-currency-{{ currency_index }}-{{ side }}-{{ line_item_index }}-description" type="hidden" name="currency-{{ currency_index }}-{{ side }}-{{ line_item_index }}-description" value="{{ form.description.data|accounting_default }}">
-  <input id="accounting-currency-{{ currency_index }}-{{ side }}-{{ line_item_index }}-amount" type="hidden" name="currency-{{ currency_index }}-{{ side }}-{{ line_item_index }}-amount" value="{{ form.amount.data|accounting_voucher_format_amount_input }}" data-min="{{ form.offset_total|accounting_default("0") }}">
+  <input id="accounting-currency-{{ currency_index }}-{{ debit_credit }}-{{ line_item_index }}-no" type="hidden" name="currency-{{ currency_index }}-{{ debit_credit }}-{{ line_item_index }}-no" value="{{ line_item_index }}">
+  <input id="accounting-currency-{{ currency_index }}-{{ debit_credit }}-{{ line_item_index }}-original-line-item-id" class="accounting-original-line-item-id" type="hidden" name="currency-{{ currency_index }}-{{ debit_credit }}-{{ line_item_index }}-original_line_item_id" value="{{ form.original_line_item_id.data|accounting_default }}" data-date="{{ form.original_line_item_date|accounting_default }}" data-text="{{ form.original_line_item_text|accounting_default }}">
+  <input id="accounting-currency-{{ currency_index }}-{{ debit_credit }}-{{ line_item_index }}-account-code" type="hidden" name="currency-{{ currency_index }}-{{ debit_credit }}-{{ line_item_index }}-account_code" value="{{ form.account_code.data|accounting_default }}" data-text="{{ form.account_text }}">
+  <input id="accounting-currency-{{ currency_index }}-{{ debit_credit }}-{{ line_item_index }}-description" type="hidden" name="currency-{{ currency_index }}-{{ debit_credit }}-{{ line_item_index }}-description" value="{{ form.description.data|accounting_default }}">
+  <input id="accounting-currency-{{ currency_index }}-{{ debit_credit }}-{{ line_item_index }}-amount" type="hidden" name="currency-{{ currency_index }}-{{ debit_credit }}-{{ line_item_index }}-amount" value="{{ form.amount.data|accounting_voucher_format_amount_input }}" data-min="{{ form.offset_total|accounting_default("0") }}">
   <div class="accounting-line-item-content">
-    <div id="accounting-currency-{{ currency_index }}-{{ side }}-{{ line_item_index }}-control" class="form-control clickable d-flex justify-content-between {% if form.all_errors %} is-invalid {% endif %}" data-bs-toggle="modal" data-bs-target="#accounting-line-item-editor-modal">
+    <div id="accounting-currency-{{ currency_index }}-{{ debit_credit }}-{{ line_item_index }}-control" class="form-control clickable d-flex justify-content-between {% if form.all_errors %} is-invalid {% endif %}" data-bs-toggle="modal" data-bs-target="#accounting-line-item-editor-modal">
       <div>
-        <div id="accounting-currency-{{ currency_index }}-{{ side }}-{{ line_item_index }}-account-text" class="small">{{ form.account_text }}</div>
-        <div id="accounting-currency-{{ currency_index }}-{{ side }}-{{ line_item_index }}-description-text">{{ form.description.data|accounting_default }}</div>
-        <div id="accounting-currency-{{ currency_index }}-{{ side }}-{{ line_item_index }}-original-line-item-text" class="fst-italic small accounting-original-line-item {% if not form.original_line_item_id.data %} d-none {% endif %}">
+        <div id="accounting-currency-{{ currency_index }}-{{ debit_credit }}-{{ line_item_index }}-account-text" class="small">{{ form.account_text }}</div>
+        <div id="accounting-currency-{{ currency_index }}-{{ debit_credit }}-{{ line_item_index }}-description-text">{{ form.description.data|accounting_default }}</div>
+        <div id="accounting-currency-{{ currency_index }}-{{ debit_credit }}-{{ line_item_index }}-original-line-item-text" class="fst-italic small accounting-original-line-item {% if not form.original_line_item_id.data %} d-none {% endif %}">
           {% if form.original_line_item_id.data %}{{ A_("Offset %(item)s", item=form.original_line_item_text|accounting_default) }}{% endif %}
         </div>
-        <div id="accounting-currency-{{ currency_index }}-{{ side }}-{{ line_item_index }}-offsets" class="fst-italic small accounting-offset-line-items {% if not form.is_need_offset %} d-none {% endif %}">
+        <div id="accounting-currency-{{ currency_index }}-{{ debit_credit }}-{{ line_item_index }}-offsets" class="fst-italic small accounting-offset-line-items {% if not form.is_need_offset %} d-none {% endif %}">
           {% if form.offsets %}
             <div class="d-flex justify-content-between {% if not form.offsets %} d-none {% endif %}">
               <div>{{ A_("Offsets") }}</div>
@@ -60,13 +60,13 @@ First written: 2023/2/25
           {% endif %}
         </div>
       </div>
-      <div><span id="accounting-currency-{{ currency_index }}-{{ side }}-{{ line_item_index }}-amount-text" class="badge rounded-pill bg-primary">{{ form.amount.data|accounting_format_amount }}</span></div>
+      <div><span id="accounting-currency-{{ currency_index }}-{{ debit_credit }}-{{ line_item_index }}-amount-text" class="badge rounded-pill bg-primary">{{ form.amount.data|accounting_format_amount }}</span></div>
     </div>
-    <div id="accounting-currency-{{ currency_index }}-{{ side }}-{{ line_item_index }}-error" class="invalid-feedback">{% if form.all_errors %}{{ form.all_errors[0] }}{% endif %}</div>
+    <div id="accounting-currency-{{ currency_index }}-{{ debit_credit }}-{{ line_item_index }}-error" class="invalid-feedback">{% if form.all_errors %}{{ form.all_errors[0] }}{% endif %}</div>
   </div>
 
   <div>
-    <button id="accounting-currency-{{ currency_index }}-{{ side }}-{{ line_item_index }}-delete" class="btn btn-danger rounded-circle {% if only_one_form or form.offsets %} d-none {% endif %}" type="button" data-target="accounting-currency-{{ currency_index }}-{{ side }}-{{ line_item_index }}">
+    <button id="accounting-currency-{{ currency_index }}-{{ debit_credit }}-{{ line_item_index }}-delete" class="btn btn-danger rounded-circle {% if only_one_form or form.offsets %} d-none {% endif %}" type="button" data-target="accounting-currency-{{ currency_index }}-{{ debit_credit }}-{{ line_item_index }}">
       <i class="fas fa-minus"></i>
     </button>
   </div>
diff --git a/src/accounting/templates/accounting/voucher/include/original-line-item-selector-modal.html b/src/accounting/templates/accounting/voucher/include/original-line-item-selector-modal.html
index 5bae39c..a9fee6c 100644
--- a/src/accounting/templates/accounting/voucher/include/original-line-item-selector-modal.html
+++ b/src/accounting/templates/accounting/voucher/include/original-line-item-selector-modal.html
@@ -37,7 +37,7 @@ First written: 2023/2/25
 
         <ul id="accounting-original-line-item-selector-option-list" class="list-group accounting-selector-list">
           {% for line_item in form.original_line_item_options %}
-            <li id="accounting-original-line-item-selector-option-{{ line_item.id }}" class="list-group-item d-flex justify-content-between accounting-clickable accounting-original-line-item-selector-option" data-id="{{ line_item.id }}" data-date="{{ line_item.voucher.date }}" data-side="{{ "debit" if line_item.is_debit else "credit" }}" data-currency-code="{{ line_item.currency.code }}" data-account-code="{{ line_item.account_code }}" data-account-text="{{ line_item.account }}" data-description="{{ line_item.description|accounting_default }}" data-net-balance="{{ line_item.net_balance|accounting_voucher_format_amount_input }}" data-text="{{ line_item }}" data-query-values="{{ line_item.query_values|tojson|forceescape }}" data-bs-toggle="modal" data-bs-target="#accounting-line-item-editor-modal">
+            <li id="accounting-original-line-item-selector-option-{{ line_item.id }}" class="list-group-item d-flex justify-content-between accounting-clickable accounting-original-line-item-selector-option" data-id="{{ line_item.id }}" data-date="{{ line_item.voucher.date }}" data-debit-credit="{{ "debit" if line_item.is_debit else "credit" }}" data-currency-code="{{ line_item.currency.code }}" data-account-code="{{ line_item.account_code }}" data-account-text="{{ line_item.account }}" data-description="{{ line_item.description|accounting_default }}" data-net-balance="{{ line_item.net_balance|accounting_voucher_format_amount_input }}" data-text="{{ line_item }}" data-query-values="{{ line_item.query_values|tojson|forceescape }}" data-bs-toggle="modal" data-bs-target="#accounting-line-item-editor-modal">
               <div>{{ line_item.voucher.date|accounting_format_date }} {{ line_item.description|accounting_default }}</div>
               <div>
                 <span class="badge bg-primary rounded-pill">
diff --git a/src/accounting/templates/accounting/voucher/receipt/include/form-currency-item.html b/src/accounting/templates/accounting/voucher/receipt/include/form-currency-item.html
index a529a82..e45e43c 100644
--- a/src/accounting/templates/accounting/voucher/receipt/include/form-currency-item.html
+++ b/src/accounting/templates/accounting/voucher/receipt/include/form-currency-item.html
@@ -47,7 +47,7 @@ First written: 2023/2/25
         <ul id="accounting-currency-{{ currency_index }}-credit-list" class="list-group accounting-line-item-list">
           {% for line_item_form in credit_forms %}
             {% with currency_index = currency_index,
-                    side = "credit",
+                    debit_credit = "credit",
                     line_item_index = loop.index,
                     only_one_line_item_form = credit_forms|length == 1,
                     form = line_item_form.form %}
@@ -62,7 +62,7 @@ First written: 2023/2/25
         </div>
 
         <div>
-          <button id="accounting-currency-{{ currency_index }}-credit-add-line-item" class="btn btn-primary" type="button" data-currency-index="{{ currency_index }}" data-side="credit" data-bs-toggle="modal" data-bs-target="#accounting-line-item-editor-modal">
+          <button id="accounting-currency-{{ currency_index }}-credit-add-line-item" class="btn btn-primary" type="button" data-currency-index="{{ currency_index }}" data-debit-credit="credit" data-bs-toggle="modal" data-bs-target="#accounting-line-item-editor-modal">
             <i class="fas fa-plus"></i>
             {{ A_("New") }}
           </button>
diff --git a/src/accounting/templates/accounting/voucher/receipt/include/form.html b/src/accounting/templates/accounting/voucher/receipt/include/form.html
index 8bfc6b0..6ae51c6 100644
--- a/src/accounting/templates/accounting/voucher/receipt/include/form.html
+++ b/src/accounting/templates/accounting/voucher/receipt/include/form.html
@@ -50,7 +50,7 @@ First written: 2023/2/25
   {% with description_editor = form.description_editor.credit %}
     {% include "accounting/voucher/include/description-editor-modal.html" %}
   {% endwith %}
-  {% with side = "credit",
+  {% with debit_credit = "credit",
           account_options = form.credit_account_options %}
     {% include "accounting/voucher/include/account-selector-modal.html" %}
   {% endwith %}
diff --git a/src/accounting/templates/accounting/voucher/transfer/include/form-currency-item.html b/src/accounting/templates/accounting/voucher/transfer/include/form-currency-item.html
index b43c772..926318e 100644
--- a/src/accounting/templates/accounting/voucher/transfer/include/form-currency-item.html
+++ b/src/accounting/templates/accounting/voucher/transfer/include/form-currency-item.html
@@ -49,7 +49,7 @@ First written: 2023/2/25
           <ul id="accounting-currency-{{ currency_index }}-debit-list" class="list-group accounting-line-item-list">
             {% for line_item_form in debit_forms %}
               {% with currency_index = currency_index,
-                      side = "debit",
+                      debit_credit = "debit",
                       line_item_index = loop.index,
                       only_one_line_item_form = debit_forms|length == 1,
                       form = line_item_form.form %}
@@ -64,7 +64,7 @@ First written: 2023/2/25
           </div>
 
           <div>
-            <button id="accounting-currency-{{ currency_index }}-debit-add-line-item" class="btn btn-primary" type="button" data-currency-index="{{ currency_index }}" data-side="debit" data-bs-toggle="modal" data-bs-target="#accounting-line-item-editor-modal">
+            <button id="accounting-currency-{{ currency_index }}-debit-add-line-item" class="btn btn-primary" type="button" data-currency-index="{{ currency_index }}" data-debit-credit="debit" data-bs-toggle="modal" data-bs-target="#accounting-line-item-editor-modal">
               <i class="fas fa-plus"></i>
               {{ A_("New") }}
             </button>
@@ -80,7 +80,7 @@ First written: 2023/2/25
           <ul id="accounting-currency-{{ currency_index }}-credit-list" class="list-group accounting-line-item-list">
             {% for line_item_form in credit_forms %}
               {% with currency_index = currency_index,
-                      side = "credit",
+                      debit_credit = "credit",
                       line_item_index = loop.index,
                       only_one_line_item_form = credit_forms|length == 1,
                       form = line_item_form.form %}
@@ -95,7 +95,7 @@ First written: 2023/2/25
           </div>
 
           <div>
-            <button id="accounting-currency-{{ currency_index }}-credit-add-line-item" class="btn btn-primary" type="button" data-currency-index="{{ currency_index }}" data-side="credit" data-bs-toggle="modal" data-bs-target="#accounting-line-item-editor-modal">
+            <button id="accounting-currency-{{ currency_index }}-credit-add-line-item" class="btn btn-primary" type="button" data-currency-index="{{ currency_index }}" data-debit-credit="credit" data-bs-toggle="modal" data-bs-target="#accounting-line-item-editor-modal">
               <i class="fas fa-plus"></i>
               {{ A_("New") }}
             </button>
diff --git a/src/accounting/templates/accounting/voucher/transfer/include/form.html b/src/accounting/templates/accounting/voucher/transfer/include/form.html
index ec9297f..f7c498c 100644
--- a/src/accounting/templates/accounting/voucher/transfer/include/form.html
+++ b/src/accounting/templates/accounting/voucher/transfer/include/form.html
@@ -57,11 +57,11 @@ First written: 2023/2/25
   {% with description_editor = form.description_editor.credit %}
     {% include "accounting/voucher/include/description-editor-modal.html" %}
   {% endwith %}
-  {% with side = "debit",
+  {% with debit_credit = "debit",
           account_options = form.debit_account_options %}
     {% include "accounting/voucher/include/account-selector-modal.html" %}
   {% endwith %}
-  {% with side = "credit",
+  {% with debit_credit = "credit",
           account_options = form.credit_account_options %}
     {% include "accounting/voucher/include/account-selector-modal.html" %}
   {% endwith %}
diff --git a/src/accounting/voucher/forms/line_item.py b/src/accounting/voucher/forms/line_item.py
index 4e0093c..bc24e63 100644
--- a/src/accounting/voucher/forms/line_item.py
+++ b/src/accounting/voucher/forms/line_item.py
@@ -53,9 +53,9 @@ class OriginalLineItemExists:
                 "The original line item does not exist."))
 
 
-class OriginalLineItemOppositeSide:
+class OriginalLineItemOppositeDebitCredit:
     """The validator to check if the original line item is on the opposite
-    side."""
+    debit or credit."""
 
     def __call__(self, form: FlaskForm, field: IntegerField) -> None:
         if field.data is None:
@@ -71,7 +71,7 @@ class OriginalLineItemOppositeSide:
                 and not original_line_item.is_debit:
             return
         raise ValidationError(lazy_gettext(
-            "The original line item is on the same side."))
+            "The original line item is on the same debit or credit."))
 
 
 class OriginalLineItemNeedOffset:
@@ -180,7 +180,7 @@ class KeepAccountWhenHavingOffset:
 
 class NotStartPayableFromDebit:
     """The validator to check that a payable line item does not start from
-    the debit side."""
+    debit."""
 
     def __call__(self, form: FlaskForm, field: StringField) -> None:
         assert isinstance(form, DebitLineItemForm)
@@ -191,12 +191,12 @@ class NotStartPayableFromDebit:
         account: Account | None = Account.find_by_code(field.data)
         if account is not None and account.is_need_offset:
             raise ValidationError(lazy_gettext(
-                "A payable line item cannot start from the debit side."))
+                "A payable line item cannot start from debit."))
 
 
 class NotStartReceivableFromCredit:
     """The validator to check that a receivable line item does not start
-    from the credit side."""
+    from credit."""
 
     def __call__(self, form: FlaskForm, field: StringField) -> None:
         assert isinstance(form, CreditLineItemForm)
@@ -207,7 +207,7 @@ class NotStartReceivableFromCredit:
         account: Account | None = Account.find_by_code(field.data)
         if account is not None and account.is_need_offset:
             raise ValidationError(lazy_gettext(
-                "A receivable line item cannot start from the credit side."))
+                "A receivable line item cannot start from credit."))
 
 
 class PositiveAmount:
@@ -439,7 +439,7 @@ class DebitLineItemForm(LineItemForm):
     original_line_item_id = IntegerField(
         validators=[Optional(),
                     OriginalLineItemExists(),
-                    OriginalLineItemOppositeSide(),
+                    OriginalLineItemOppositeDebitCredit(),
                     OriginalLineItemNeedOffset(),
                     OriginalLineItemNotOffset()])
     """The ID of the original line item."""
@@ -489,7 +489,7 @@ class CreditLineItemForm(LineItemForm):
     original_line_item_id = IntegerField(
         validators=[Optional(),
                     OriginalLineItemExists(),
-                    OriginalLineItemOppositeSide(),
+                    OriginalLineItemOppositeDebitCredit(),
                     OriginalLineItemNeedOffset(),
                     OriginalLineItemNotOffset()])
     """The ID of the original line item."""
diff --git a/src/accounting/voucher/forms/voucher.py b/src/accounting/voucher/forms/voucher.py
index c792845..77a1bda 100644
--- a/src/accounting/voucher/forms/voucher.py
+++ b/src/accounting/voucher/forms/voucher.py
@@ -376,7 +376,7 @@ class LineItemCollector(t.Generic[T], ABC):
 
     def _make_cash_line_item(self, forms: list[LineItemForm], is_debit: bool,
                              currency_code: str, no: int) -> None:
-        """Composes the cash line item at the other side of the cash
+        """Composes the cash line item at the other debit or credit of the cash
         voucher.
 
         :param forms: The line item forms in the same currency.
diff --git a/src/accounting/voucher/utils/description_editor.py b/src/accounting/voucher/utils/description_editor.py
index 564e163..9ae4826 100644
--- a/src/accounting/voucher/utils/description_editor.py
+++ b/src/accounting/voucher/utils/description_editor.py
@@ -143,16 +143,16 @@ class DescriptionType:
         return sorted(self.__tag_dict.values(), key=lambda x: -x.freq)
 
 
-class DescriptionSide:
-    """A description side"""
+class DescriptionDebitCredit:
+    """The description on debit or credit."""
 
-    def __init__(self, side_id: t.Literal["debit", "credit"]):
-        """Constructs a description side.
+    def __init__(self, debit_credit: t.Literal["debit", "credit"]):
+        """Constructs the description on debit or credit.
 
-        :param side_id: The side ID, either "debit" or "credit".
+        :param debit_credit: Either "debit" or "credit".
         """
-        self.side: t.Literal["debit", "credit"] = side_id
-        """The side."""
+        self.debit_credit: t.Literal["debit", "credit"] = debit_credit
+        """Either debit or credit."""
         self.general: DescriptionType = DescriptionType("general")
         """The general tags."""
         self.travel: DescriptionType = DescriptionType("travel")
@@ -179,7 +179,7 @@ class DescriptionSide:
     @property
     def accounts(self) -> list[DescriptionAccount]:
         """Returns the suggested accounts of all tags in the description editor
-        in the side, in their frequency order.
+        in debit or credit, in their frequency order.
 
         :return: The suggested accounts of all tags, in their frequency order.
         """
@@ -202,12 +202,12 @@ class DescriptionEditor:
 
     def __init__(self):
         """Constructs the description editor."""
-        self.debit: DescriptionSide = DescriptionSide("debit")
+        self.debit: DescriptionDebitCredit = DescriptionDebitCredit("debit")
         """The debit tags."""
-        self.credit: DescriptionSide = DescriptionSide("credit")
+        self.credit: DescriptionDebitCredit = DescriptionDebitCredit("credit")
         """The credit tags."""
-        side: sa.Label = sa.case((VoucherLineItem.is_debit, "debit"),
-                                 else_="credit").label("side")
+        debit_credit: sa.Label = sa.case((VoucherLineItem.is_debit, "debit"),
+                                         else_="credit").label("debit_credit")
         tag_type: sa.Label = sa.case(
             (VoucherLineItem.description.like("_%—_%—_%→_%"), "bus"),
             (sa.or_(VoucherLineItem.description.like("_%—_%→_%"),
@@ -215,21 +215,22 @@ class DescriptionEditor:
             else_="general").label("tag_type")
         tag: sa.Label = get_prefix(VoucherLineItem.description, "—")\
             .label("tag")
-        select: sa.Select = sa.Select(side, tag_type, tag,
+        select: sa.Select = sa.Select(debit_credit, tag_type, tag,
                                       VoucherLineItem.account_id,
                                       sa.func.count().label("freq"))\
             .filter(VoucherLineItem.description.is_not(None),
                     VoucherLineItem.description.like("_%—_%"),
                     VoucherLineItem.original_line_item_id.is_(None))\
-            .group_by(side, tag_type, tag, VoucherLineItem.account_id)
+            .group_by(debit_credit, tag_type, tag, VoucherLineItem.account_id)
         result: list[sa.Row] = db.session.execute(select).all()
         accounts: dict[int, Account] \
             = {x.id: x for x in Account.query
                .filter(Account.id.in_({x.account_id for x in result})).all()}
-        side_dict: dict[t.Literal["debit", "credit"], DescriptionSide] \
-            = {x.side: x for x in {self.debit, self.credit}}
+        debit_credit_dict: dict[t.Literal["debit", "credit"],
+                                DescriptionDebitCredit] \
+            = {x.debit_credit: x for x in {self.debit, self.credit}}
         for row in result:
-            side_dict[row.side].add_tag(
+            debit_credit_dict[row.debit_credit].add_tag(
                 row.tag_type, row.tag, accounts[row.account_id], row.freq)
 
 
diff --git a/src/accounting/voucher/utils/operators.py b/src/accounting/voucher/utils/operators.py
index 96319e5..42771b5 100644
--- a/src/accounting/voucher/utils/operators.py
+++ b/src/accounting/voucher/utils/operators.py
@@ -87,7 +87,7 @@ class VoucherOperator(ABC):
         return render_template(
             "accounting/voucher/include/form-line-item.html",
             currency_index="CURRENCY_INDEX",
-            side="SIDE",
+            debit_credit="DEBIT_CREDIT",
             line_item_index="LINE_ITEM_INDEX",
             form=LineItemForm())
 
diff --git a/tests/test_offset.py b/tests/test_offset.py
index 0858b9e..16266a4 100644
--- a/tests/test_offset.py
+++ b/tests/test_offset.py
@@ -101,7 +101,7 @@ class OffsetTestCase(unittest.TestCase):
         self.assertEqual(response.status_code, 302)
         self.assertEqual(response.headers["Location"], create_uri)
 
-        # The same side
+        # The same debit or credit
         form = voucher_data.new_form(self.csrf_token)
         form["currency-1-credit-1-original_line_item_id"] \
             = self.data.e_p_or1c.id
@@ -210,7 +210,7 @@ class OffsetTestCase(unittest.TestCase):
         self.assertEqual(response.status_code, 302)
         self.assertEqual(response.headers["Location"], edit_uri)
 
-        # The same side
+        # The same debit or credit
         form = voucher_data.update_form(self.csrf_token)
         form["currency-1-credit-1-original_line_item_id"] \
             = self.data.e_p_or1c.id
@@ -417,7 +417,7 @@ class OffsetTestCase(unittest.TestCase):
         self.assertEqual(response.status_code, 302)
         self.assertEqual(response.headers["Location"], create_uri)
 
-        # The same side
+        # The same debit or credit
         form = voucher_data.new_form(self.csrf_token)
         form["currency-1-debit-1-original_line_item_id"] \
             = self.data.e_r_or1d.id
@@ -524,7 +524,7 @@ class OffsetTestCase(unittest.TestCase):
         self.assertEqual(response.status_code, 302)
         self.assertEqual(response.headers["Location"], edit_uri)
 
-        # The same side
+        # The same debit or credit
         form = voucher_data.update_form(self.csrf_token)
         form["currency-1-debit-1-original_line_item_id"] \
             = self.data.e_r_or1d.id
diff --git a/tests/test_voucher.py b/tests/test_voucher.py
index 569098d..ca62915 100644
--- a/tests/test_voucher.py
+++ b/tests/test_voucher.py
@@ -231,7 +231,7 @@ class CashReceiptVoucherTestCase(unittest.TestCase):
         self.assertEqual(response.status_code, 302)
         self.assertEqual(response.headers["Location"], create_uri)
 
-        # A receivable line item cannot start from the credit side
+        # A receivable line item cannot start from credit
         form = self.__get_add_form()
         key: str = [x for x in form.keys()
                     if x.endswith("-account_code") and "-credit-" in x][0]
@@ -391,7 +391,7 @@ class CashReceiptVoucherTestCase(unittest.TestCase):
         self.assertEqual(response.status_code, 302)
         self.assertEqual(response.headers["Location"], edit_uri)
 
-        # A receivable line item cannot start from the credit side
+        # A receivable line item cannot start from credit
         form = self.__get_add_form()
         key: str = [x for x in form.keys()
                     if x.endswith("-account_code") and "-credit-" in x][0]
@@ -803,7 +803,7 @@ class CashDisbursementVoucherTestCase(unittest.TestCase):
         self.assertEqual(response.status_code, 302)
         self.assertEqual(response.headers["Location"], create_uri)
 
-        # A payable line item cannot start from the debit side
+        # A payable line item cannot start from debit
         form = self.__get_add_form()
         key: str = [x for x in form.keys()
                     if x.endswith("-account_code") and "-debit-" in x][0]
@@ -966,7 +966,7 @@ class CashDisbursementVoucherTestCase(unittest.TestCase):
         self.assertEqual(response.status_code, 302)
         self.assertEqual(response.headers["Location"], edit_uri)
 
-        # A payable line item cannot start from the debit side
+        # A payable line item cannot start from debit
         form = self.__get_add_form()
         key: str = [x for x in form.keys()
                     if x.endswith("-account_code") and "-debit-" in x][0]
@@ -1398,7 +1398,7 @@ class TransferVoucherTestCase(unittest.TestCase):
         self.assertEqual(response.status_code, 302)
         self.assertEqual(response.headers["Location"], create_uri)
 
-        # A receivable line item cannot start from the credit side
+        # A receivable line item cannot start from credit
         form = self.__get_add_form()
         key: str = [x for x in form.keys()
                     if x.endswith("-account_code") and "-credit-" in x][0]
@@ -1407,7 +1407,7 @@ class TransferVoucherTestCase(unittest.TestCase):
         self.assertEqual(response.status_code, 302)
         self.assertEqual(response.headers["Location"], create_uri)
 
-        # A payable line item cannot start from the debit side
+        # A payable line item cannot start from debit
         form = self.__get_add_form()
         key: str = [x for x in form.keys()
                     if x.endswith("-account_code") and "-debit-" in x][0]
@@ -1597,7 +1597,7 @@ class TransferVoucherTestCase(unittest.TestCase):
         self.assertEqual(response.status_code, 302)
         self.assertEqual(response.headers["Location"], edit_uri)
 
-        # A receivable line item cannot start from the credit side
+        # A receivable line item cannot start from credit
         form = self.__get_add_form()
         key: str = [x for x in form.keys()
                     if x.endswith("-account_code") and "-credit-" in x][0]
@@ -1606,7 +1606,7 @@ class TransferVoucherTestCase(unittest.TestCase):
         self.assertEqual(response.status_code, 302)
         self.assertEqual(response.headers["Location"], edit_uri)
 
-        # A payable line item cannot start from the debit side
+        # A payable line item cannot start from debit
         form = self.__get_add_form()
         key: str = [x for x in form.keys()
                     if x.endswith("-account_code") and "-debit-" in x][0]
diff --git a/tests/testlib_offset.py b/tests/testlib_offset.py
index 2767490..b3947b8 100644
--- a/tests/testlib_offset.py
+++ b/tests/testlib_offset.py
@@ -50,17 +50,17 @@ class VoucherLineItemData:
         self.description: str = description
         self.amount: Decimal = Decimal(amount)
 
-    def form(self, prefix: str, side: str, index: int, is_update: bool) \
-            -> dict[str, str]:
+    def form(self, prefix: str, debit_credit: str, index: int,
+             is_update: bool) -> dict[str, str]:
         """Returns the line item as form data.
 
         :param prefix: The prefix of the form fields.
-        :param side: The side, either "debit" or "credit".
+        :param debit_credit: Either "debit" or "credit".
         :param index: The line item index.
         :param is_update: True for an update operation, or False otherwise
         :return: The form data.
         """
-        prefix = f"{prefix}-{side}-{index}"
+        prefix = f"{prefix}-{debit_credit}-{index}"
         form: dict[str, str] = {f"{prefix}-account_code": self.account,
                                 f"{prefix}-description": self.description,
                                 f"{prefix}-amount": str(self.amount)}