diff --git a/Available-C#-and-.NET-features.md b/Available-C#-and-.NET-features.md
index 6976828..fdffbfa 100644
--- a/Available-C#-and-.NET-features.md
+++ b/Available-C#-and-.NET-features.md
@@ -42,6 +42,7 @@ enhanced [`params`](https://learn.microsoft.com/en-us/dotnet/csharp/language-ref
 [unified `Span`/`Array`/`List` init syntax](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/operators/collection-expressions) | ✔️ | ✔️ | encouraged
 [primary constructors](https://learn.microsoft.com/en-us/dotnet/csharp/programming-guide/classes-and-structs/instance-constructors#primary-constructors) on non-`record`s | ✔️ | ✔️ | encouraged
 ^ C# 12 ^ | 🔵 `net48` | 🟢 `ns2.0` | ---
+[user-defined `checked` operators](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/operators/arithmetic-operators#user-defined-checked-operators) | ✔️ | ✔️ | encouraged, and consider marking non-`checked` variant as `[Obsolete]`
 [`file` access modifier](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/file) | ✔️ | ✔️ | allowed
 simple [`ref` fields](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/builtin-types/ref-struct#ref-fields) | ❌ | ❌ | unsupported
 [`required` props](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/required) | ⭕ | ⭕ | disallowed