[Question]Thread Access Rights: PROCESS_SET_SESSIONID Flag

[nilum]

So as a little exercise for myself I decided to write a small library to read memory (borrowing heavily from BlackMagic).

In BlackMagic's source, in the AccessRights class, I noticed this flag commented out:

//public const uint PROCESS_SET_SESSIONID = 0x0004;

Curiously, MSDN's documentation(AND) lists nothing about this flag. Even stranger, the THREAD_ALL_ACCESS constant in BlackMagic still sets this flag to 1:

public const uint THREAD_ALL_ACCESS = STANDARD_RIGHTS_REQUIRED | SYNCHRONIZE | 0x3FF;

(Or 0x0004)

If PROCESS_SET_SESSIONID is deprecated, redundant or unsafe, wouldn't this be more proper:

public const uint THREAD_ALL_ACCESS = STANDARD_RIGHTS_REQUIRED | SYNCHRONIZE | 0x3FB;

(Xor 0x0004)

Thanks in advance.