How to tag that a class is thread-safe (or not)?

Question

In MSDN documentation we see :

Console

Thread Safety

This type is thread safe.

TextWriter

Thread Safet

Answer 1

The Sandcastle Help File Builder project contains a useful XML Comments Guide.

It documents the threadsafety tag:

<threadsafety static="true|false" instance="true|false"/>

The root SHFB documentation page is here.

Answer 2

Add this detail to the <summary> or <remarks> tags.

There is no specific tag or convention on how to indicate a class is thread safe - you need to write it in your documentation.