diff --git a/CHANGELOG.md b/CHANGELOG.md
index ce3046fd..ea003c7d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@
 <h2>Version 3.1.0 - ??/??/2025</h2>
       <ul>
         <li>Added Google Gemini API support [<a href="https://github.com/micz/ThunderAI/issues/204">#204</a>, <a href="https://github.com/micz/ThunderAI/issues/217">#2174</a>].</li>
+        <li>Added an info text about using the new <i>{%tags_full_list%}</i> placeholder in the "Add Tags Prompt" page [<a href="https://github.com/micz/ThunderAI/issues/215">#215</a>].</li>
         <li>...</li>
       </ul>
 <h2>Version 3.0.0 - 05/01/2025</h2>
diff --git a/_locales/en/messages.json b/_locales/en/messages.json
index 405791b3..56ad5422 100644
--- a/_locales/en/messages.json
+++ b/_locales/en/messages.json
@@ -945,6 +945,8 @@
   },
   "ChatGPT_Developer_Messages_Info": {
     "message": "When you set the developer messages, you give the model additional context to understand the task, provide more customized responses, and adhere to specific guidelines over the prompt that will be sent.",
+  "prefs_OptionText_btnManagePrompts_infoline3": {
+    "message": "You can use the {%tags_full_list%} data placeholder in the prompt to list the available tags. With an appropriate prompt, you could then force the tags to be chosen only from the list of those already existing.",
     "description": ""
   }
 }
\ No newline at end of file
diff --git a/options/mzta-release-notes.html b/options/mzta-release-notes.html
index bdf3a282..1f3ee74f 100644
--- a/options/mzta-release-notes.html
+++ b/options/mzta-release-notes.html
@@ -10,6 +10,7 @@
       <h2>Version 3.1.0 - ??/??/2025</h2>
       <ul>
         <li>Added Google Gemini API support [<a href="https://github.com/micz/ThunderAI/issues/204">#204</a>, <a href="https://github.com/micz/ThunderAI/issues/217">#2174</a>].</li>
+        <li>Added an info text about using the new <i>{%tags_full_list%}</i> placeholder in the "Add Tags Prompt" page [<a href="https://github.com/micz/ThunderAI/issues/215">#215</a>].</li>
         <li>...</li>
       </ul>
       <h2>Version 3.0.0 - 05/01/2025</h2>
diff --git a/pages/addtags/mzta-add-tags.html b/pages/addtags/mzta-add-tags.html
index c85d8b06..f7e0f81f 100644
--- a/pages/addtags/mzta-add-tags.html
+++ b/pages/addtags/mzta-add-tags.html
@@ -53,7 +53,8 @@
     <div id="addtags_prompt_container">
         <span class="section_title">__MSG_AddTags_prompt_text_title__</span><span id="addtags_prompt_unsaved" class="unsaved hidden"> __MSG_customPrompts_unsaved_changes__</span>
         <br><span class="infoline">__MSG_prefs_OptionText_btnManagePrompts_infoline__ <a href="https://micz.it/thunderbird-addon-thunderai/data-placeholders/">__MSG_customPrompts_managePrompts_help__</a>
-        <br><b>__MSG_prefs_OptionText_btnManagePrompts_infoline2__</b></span>
+          <br>__MSG_prefs_OptionText_btnManagePrompts_infoline3__
+          <br><b>__MSG_prefs_OptionText_btnManagePrompts_infoline2__</b></span>
         <br>
         <div class="autocomplete-container">
             <textarea id="addtags_prompt_text" rows="15"></textarea>