diff --git a/frontend/src/components/dialog/about-dialog.js b/frontend/src/components/dialog/about-dialog.js
index 61416a5794..c0165df475 100644
--- a/frontend/src/components/dialog/about-dialog.js
+++ b/frontend/src/components/dialog/about-dialog.js
@@ -1,7 +1,7 @@
 import React from 'react';
 import PropTypes from 'prop-types';
 import { Modal, ModalBody } from 'reactstrap';
-import { gettext, lang, mediaUrl, logoPath, logoWidth, logoHeight, siteTitle, seafileVersion, extraAboutDialogLinks } from '../../utils/constants';
+import { gettext, lang, mediaUrl, logoPath, logoWidth, logoHeight, siteTitle, seafileVersion, additionalAboutDialogLinks } from '../../utils/constants';
 
 const propTypes = {
   onCloseAboutDialog: PropTypes.func.isRequired,
@@ -14,10 +14,10 @@ class AboutDialog extends React.Component {
   }
 
   renderExternalAboutLinks = () => {
-    if (extraAboutDialogLinks && (typeof extraAboutDialogLinks) === 'object') {
-      let keys = Object.keys(extraAboutDialogLinks);
+    if (additionalAboutDialogLinks && (typeof additionalAboutDialogLinks) === 'object') {
+      let keys = Object.keys(additionalAboutDialogLinks);
       return keys.map((key, index) => {
-        return <a key={index} className="d-block" href={extraAboutDialogLinks[key]}>{key}</a>;
+        return <a key={index} className="d-block" href={additionalAboutDialogLinks[key]}>{key}</a>;
       });
     }
     return null;
diff --git a/frontend/src/components/dialog/share-dialog.js b/frontend/src/components/dialog/share-dialog.js
index 607e0280dc..dfeedb3ead 100644
--- a/frontend/src/components/dialog/share-dialog.js
+++ b/frontend/src/components/dialog/share-dialog.js
@@ -1,7 +1,7 @@
 import React, { Fragment } from 'react';
 import PropTypes from 'prop-types';
 import { Modal, ModalHeader, ModalBody, TabContent, TabPane, Nav, NavItem, NavLink } from 'reactstrap'; 
-import { gettext, username, canGenerateShareLink, canGenerateUploadLink, extraShareDialogNote } from '../../utils/constants';
+import { gettext, username, canGenerateShareLink, canGenerateUploadLink, additionalShareDialogNote } from '../../utils/constants';
 import ShareToUser from './share-to-user';
 import ShareToGroup from './share-to-group';
 import GenerateShareLink from './generate-share-link';
@@ -208,11 +208,11 @@ class ShareDialog extends React.Component {
   }
 
   renderExternalShareMessage = () => {
-    if (extraShareDialogNote && (typeof extraShareDialogNote) === 'object') {
+    if (additionalShareDialogNote && (typeof additionalShareDialogNote) === 'object') {
       return (
         <div className="external-share-message mt-2">
-          <h6>{extraShareDialogNote.title}</h6>
-          <div style={{fontSize: '14px', color: '#666'}}>{extraShareDialogNote.content}</div>
+          <h6>{additionalShareDialogNote.title}</h6>
+          <div style={{fontSize: '14px', color: '#666'}}>{additionalShareDialogNote.content}</div>
         </div>
       );
     }
diff --git a/frontend/src/components/side-nav-footer.js b/frontend/src/components/side-nav-footer.js
index d0f89f93d4..188a6d55b3 100644
--- a/frontend/src/components/side-nav-footer.js
+++ b/frontend/src/components/side-nav-footer.js
@@ -1,5 +1,5 @@
 import React, { Fragment } from 'react';
-import { gettext, siteRoot, sideNavFooterCustomHtml, extraAppBottomLinks } from '../utils/constants';
+import { gettext, siteRoot, sideNavFooterCustomHtml, additionalAppBottomLinks } from '../utils/constants';
 import ModalPortal from './modal-portal';
 import AboutDialog from './dialog/about-dialog';
 
@@ -17,10 +17,10 @@ class SideNavFooter extends React.Component {
   }
 
   renderExternalAppLinks = () => {
-    if (extraAppBottomLinks && (typeof extraAppBottomLinks) === 'object') {
-      let keys = Object.keys(extraAppBottomLinks);
+    if (additionalAppBottomLinks && (typeof additionalAppBottomLinks) === 'object') {
+      let keys = Object.keys(additionalAppBottomLinks);
       return keys.map((key, index) => {
-        return <a key={index} className="item" href={extraAppBottomLinks[key]}>{key}</a>;
+        return <a key={index} className="item" href={additionalAppBottomLinks[key]}>{key}</a>;
       });
     }
     return null;
@@ -37,7 +37,7 @@ class SideNavFooter extends React.Component {
           <a href={siteRoot + 'help/'} target="_blank" rel="noopener noreferrer" className="item">{gettext('Help')}</a>
           <a className="item cursor-pointer" onClick={this.onAboutDialogToggle}>{gettext('About')}</a>
           {this.renderExternalAppLinks()}
-          <a href={siteRoot + 'download_client_program/'} className={`item ${extraAppBottomLinks ? '' : 'last-item'}`}>
+          <a href={siteRoot + 'download_client_program/'} className={`item ${additionalAppBottomLinks ? '' : 'last-item'}`}>
             <span aria-hidden="true" className="sf2-icon-monitor vam"></span>{' '}
             <span className="vam">{gettext('Clients')}</span>
           </a>
diff --git a/frontend/src/utils/constants.js b/frontend/src/utils/constants.js
index b43ea58780..eb61f8a0b7 100644
--- a/frontend/src/utils/constants.js
+++ b/frontend/src/utils/constants.js
@@ -62,9 +62,9 @@ export const curNoteMsg = window.app.pageOptions.curNoteMsg;
 export const curNoteID = window.app.pageOptions.curNoteID;
 
 export const showLogoutIcon = window.app.pageOptions.showLogoutIcon;
-export const extraShareDialogNote = window.app.pageOptions.extraShareDialogNote;
-export const extraAppBottomLinks = window.app.pageOptions.extraAppBottomLinks;
-export const extraAboutDialogLinks = window.app.pageOptions.extraAboutDialogLinks;
+export const additionalShareDialogNote = window.app.pageOptions.additionalShareDialogNote;
+export const additionalAppBottomLinks = window.app.pageOptions.additionalAppBottomLinks;
+export const additionalAboutDialogLinks = window.app.pageOptions.additionalAboutDialogLinks;
 
 // wiki
 export const slug = window.wiki ? window.wiki.config.slug : '';
diff --git a/seahub/settings.py b/seahub/settings.py
index 9d08b8e1c4..68fbf03de6 100644
--- a/seahub/settings.py
+++ b/seahub/settings.py
@@ -771,26 +771,26 @@ ENABLE_REPO_SNAPSHOT_LABEL = False
 ENABLE_REPO_WIKI_MODE = True
 
 ############################
-# HU berlin external#
+# HU berlin additional #
 ############################
 
-# EXTRA_SHARE_DIALOG_NOTE = {
+# ADDITIONAL_SHARE_DIALOG_NOTE = {
 #     'title': 'Attention! Read before shareing files:',
 #     'content': 'Do not share personal or confidential official data with **.'
 # }
-EXTRA_SHARE_DIALOG_NOTE = None
+ADDITIONAL_SHARE_DIALOG_NOTE = None
 
-# EXTRA_APP_BOTTOM_LINKS = {
+# ADDITIONAL_APP_BOTTOM_LINKS = {
 #     'seafile': 'http://dev.seahub.com/seahub',
 #     'dtable-web': 'http://dev.seahub.com/dtable-web'
 # }
-EXTRA_APP_BOTTOM_LINKS = None
+ADDITIONAL_APP_BOTTOM_LINKS = None
 
-# EXTRA_ABOUT_DIALOG_LINKS = {
+# ADDITIONAL_ABOUT_DIALOG_LINKS = {
 #     'seafile': 'http://dev.seahub.com/seahub',
 #     'dtable-web': 'http://dev.seahub.com/dtable-web'
 # }
-EXTRA_ABOUT_DIALOG_LINKS = None
+ADDITIONAL_ABOUT_DIALOG_LINKS = None
 
 ############################
 # Settings for SeafileDocs #
diff --git a/seahub/templates/base_for_react.html b/seahub/templates/base_for_react.html
index 7bdb151a0a..07effc53bd 100644
--- a/seahub/templates/base_for_react.html
+++ b/seahub/templates/base_for_react.html
@@ -103,9 +103,9 @@
             curNoteID: '{{ request.cur_note.id }}',
             {% endif %}
             showLogoutIcon: {% if show_logout_icon %} true {% else %} false {% endif %},
-            extraShareDialogNote: {% if extra_share_dialog_note %} {{ extra_share_dialog_note|safe }} {% else %} null {% endif %},
-            extraAppBottomLinks: {% if extra_app_bottom_links %} {{ extra_app_bottom_links|safe }} {% else %} null {% endif %},
-            extraAboutDialogLinks: {% if extra_about_dialog_links %} {{ extra_about_dialog_links|safe }} {% else %} null {% endif %}
+            additionalShareDialogNote: {% if additional_share_dialog_note %} {{ additional_share_dialog_note|safe }} {% else %} null {% endif %},
+            additionalAppBottomLinks: {% if additional_app_bottom_links %} {{ additional_app_bottom_links|safe }} {% else %} null {% endif %},
+            additionalAboutDialogLinks: {% if additional_about_dialog_links %} {{ additional_about_dialog_links|safe }} {% else %} null {% endif %}
         }
      };
 </script>
diff --git a/seahub/views/__init__.py b/seahub/views/__init__.py
index dc9c936a83..d268876c76 100644
--- a/seahub/views/__init__.py
+++ b/seahub/views/__init__.py
@@ -57,7 +57,7 @@ from seahub.settings import AVATAR_FILE_STORAGE, \
     UNREAD_NOTIFICATIONS_REQUEST_INTERVAL, SHARE_LINK_EXPIRE_DAYS_MIN, \
     SHARE_LINK_EXPIRE_DAYS_MAX, SHARE_LINK_EXPIRE_DAYS_DEFAULT, \
     SEAFILE_COLLAB_SERVER, ENABLE_RESET_ENCRYPTED_REPO_PASSWORD, \
-    EXTRA_SHARE_DIALOG_NOTE, EXTRA_APP_BOTTOM_LINKS, EXTRA_ABOUT_DIALOG_LINKS
+    ADDITIONAL_SHARE_DIALOG_NOTE, ADDITIONAL_APP_BOTTOM_LINKS, ADDITIONAL_ABOUT_DIALOG_LINKS
 
 from seahub.wopi.settings import ENABLE_OFFICE_WEB_APP
 from seahub.onlyoffice.settings import ENABLE_ONLYOFFICE
@@ -1278,7 +1278,7 @@ def react_fake_view(request, **kwargs):
         'folder_perm_enabled': folder_perm_enabled,
         'file_audit_enabled' : FILE_AUDIT_ENABLED,
         'custom_nav_items' : json.dumps(CUSTOM_NAV_ITEMS),
-        'extra_share_dialog_note': EXTRA_SHARE_DIALOG_NOTE,
-        'extra_app_bottom_links': EXTRA_APP_BOTTOM_LINKS,
-        'extra_about_dialog_links': EXTRA_ABOUT_DIALOG_LINKS
+        'additional_share_dialog_note': ADDITIONAL_SHARE_DIALOG_NOTE,
+        'additional_app_bottom_links': ADDITIONAL_APP_BOTTOM_LINKS,
+        'additional_about_dialog_links': ADDITIONAL_SHARE_DIALOG_NOTE
     })