diff --git a/instructions/aspnet-rest-apis.instructions.md b/instructions/aspnet-rest-apis.instructions.md
index c550ae38..612d3e80 100644
--- a/instructions/aspnet-rest-apis.instructions.md
+++ b/instructions/aspnet-rest-apis.instructions.md
@@ -6,7 +6,7 @@ applyTo: '**/*.cs, **/*.json'
 # ASP.NET REST API Development
 
 ## Instruction
-- Guide users through building their first REST API using ASP.NET Core 9.
+- Guide users through building their first REST API using ASP.NET Core 10.
 - Explain both traditional Web API controllers and the newer Minimal API approach.
 - Provide educational context for each implementation decision to help users understand the underlying concepts.
 - Emphasize best practices for API design, testing, documentation, and deployment.
@@ -22,11 +22,11 @@ applyTo: '**/*.cs, **/*.json'
 
 ## Project Setup and Structure
 
-- Guide users through creating a new ASP.NET Core 9 Web API project with the appropriate templates.
+- Guide users through creating a new ASP.NET Core 10 Web API project with the appropriate templates.
 - Explain the purpose of each generated file and folder to build understanding of the project structure.
 - Demonstrate how to organize code using feature folders or domain-driven design principles.
 - Show proper separation of concerns with models, services, and data access layers.
-- Explain the Program.cs and configuration system in ASP.NET Core 9 including environment-specific settings.
+- Explain the Program.cs and configuration system in ASP.NET Core 10 including environment-specific settings.
 
 ## Building Controller-Based APIs
 
@@ -66,7 +66,7 @@ applyTo: '**/*.cs, **/*.json'
 - Explain the validation pipeline and how to customize validation responses.
 - Demonstrate a global exception handling strategy using middleware.
 - Show how to create consistent error responses across the API.
-- Explain problem details (RFC 7807) implementation for standardized error responses.
+- Explain problem details (RFC 9457) implementation for standardized error responses.
 
 ## API Versioning and Documentation
 
diff --git a/instructions/csharp-ja.instructions.md b/instructions/csharp-ja.instructions.md
index 92594e49..dea3b81f 100644
--- a/instructions/csharp-ja.instructions.md
+++ b/instructions/csharp-ja.instructions.md
@@ -67,7 +67,7 @@ applyTo: '**/*.cs'
 - 検証パイプラインと、検証応答のカスタマイズ方法を説明します。
 - ミドルウェアを用いたグローバル例外処理戦略を示します。
 - API 全体で一貫したエラー応答を作成する方法を示します。
-- 標準化されたエラー応答のための Problem Details（RFC 7807）の実装を説明します。
+- 標準化されたエラー応答のための Problem Details（RFC 9457）の実装を説明します。
 
 ## API のバージョニングとドキュメント
 
diff --git a/instructions/csharp.instructions.md b/instructions/csharp.instructions.md
index 8d6f4c20..16355d2c 100644
--- a/instructions/csharp.instructions.md
+++ b/instructions/csharp.instructions.md
@@ -67,7 +67,7 @@ applyTo: '**/*.cs'
 - Explain the validation pipeline and how to customize validation responses.
 - Demonstrate a global exception handling strategy using middleware.
 - Show how to create consistent error responses across the API.
-- Explain problem details (RFC 7807) implementation for standardized error responses.
+- Explain problem details (RFC 9457) implementation for standardized error responses.
 
 ## API Versioning and Documentation