diff --git a/docs/en/releases/unreleased.ipynb b/docs/en/releases/unreleased.ipynb
index 2630db3..8a68e58 100644
--- a/docs/en/releases/unreleased.ipynb
+++ b/docs/en/releases/unreleased.ipynb
@@ -707,7 +707,8 @@
     "## Other Changes\n",
     "\n",
     "- Relaxed version bounds to allow installation on any Python 3 version from Python 3.11 onwards.\n",
-    "- Error messages for invalid comprehensions used with the Decorator API in `sum` and similar constructs now report the specific location in the source code."
+    "- Error messages for invalid comprehensions used with the Decorator API in `sum` and similar constructs now report the specific location in the source code.\n",
+    "- {py:meth}`Problem.used_placeholders <jijmodeling.Problem.used_placeholders>` has been deprecated because its purpose is unclear, and {py:class}`~jijmodeling.Compiler` also requires values for all placeholders. Use {py:meth}`Problem.placeholders <jijmodeling.Problem.placeholders>` instead."
    ]
   }
  ],
diff --git a/docs/ja/releases/unreleased.ipynb b/docs/ja/releases/unreleased.ipynb
index 21f4160..274574f 100644
--- a/docs/ja/releases/unreleased.ipynb
+++ b/docs/ja/releases/unreleased.ipynb
@@ -692,7 +692,8 @@
     "## その他の変更\n",
     "\n",
     "- バージョン条件を緩和し、Python 3.11 以降の任意の Python 3 でのインストールを許容しました。\n",
-    "- Decorator API の `sum` などで不正な内包表記を使った際のエラーメッセージが、具体的なコード上の位置を報告するようになりました。"
+    "- Decorator API の `sum` などで不正な内包表記を使った際のエラーメッセージが、具体的なコード上の位置を報告するようになりました。\n",
+    "- {py:meth}`Problem.used_placeholders <jijmodeling.Problem.used_placeholders>` は用途が明確でなく、{py:class}`~jijmodeling.Compiler` も全てのプレースホルダーの値を要求するため、廃止予定となりました。かわりに {py:meth}`Problem.placeholders <jijmodeling.Problem.placeholders>` を使用してください。"
    ]
   }
  ],
diff --git a/markdowns/en/releases/unreleased.md b/markdowns/en/releases/unreleased.md
index 7fc120d..bb8bf63 100644
--- a/markdowns/en/releases/unreleased.md
+++ b/markdowns/en/releases/unreleased.md
@@ -221,3 +221,4 @@ Starting with this release, the settings are preserved as shown above, and the b
 
 - Relaxed version bounds to allow installation on any Python 3 version from Python 3.11 onwards.
 - Error messages for invalid comprehensions used with the Decorator API in `sum` and similar constructs now report the specific location in the source code.
+- {py:meth}`Problem.used_placeholders <jijmodeling.Problem.used_placeholders>` has been deprecated because its purpose is unclear, and {py:class}`~jijmodeling.Compiler` also requires values for all placeholders. Use {py:meth}`Problem.placeholders <jijmodeling.Problem.placeholders>` instead.
diff --git a/markdowns/ja/releases/unreleased.md b/markdowns/ja/releases/unreleased.md
index fa05422..0f0cf19 100644
--- a/markdowns/ja/releases/unreleased.md
+++ b/markdowns/ja/releases/unreleased.md
@@ -216,3 +216,4 @@ problem
 
 - バージョン条件を緩和し、Python 3.11 以降の任意の Python 3 でのインストールを許容しました。
 - Decorator API の `sum` などで不正な内包表記を使った際のエラーメッセージが、具体的なコード上の位置を報告するようになりました。
+- {py:meth}`Problem.used_placeholders <jijmodeling.Problem.used_placeholders>` は用途が明確でなく、{py:class}`~jijmodeling.Compiler` も全てのプレースホルダーの値を要求するため、廃止予定となりました。かわりに {py:meth}`Problem.placeholders <jijmodeling.Problem.placeholders>` を使用してください。