Broken: 2.83 and above
Short description of error
In the Python API docs, bpy.types.WindowManager.clipboard has disappeared in release 2.83. It is not removed, it can still be used but the documentation is gone.
Disappeared in 2.83 docs: https://docs.blender.org/api/2.83/bpy.types.WindowManager.html
It's missing in every documentation from version 2.83 to the latest version.