What do “\\.\”, “\??\”, “\\?\”, “\\” mean?

Question

What I know is

\\\\.\\ 

It is used when we open a device\'s symbolic link in user mode

\\??\\ 

It is used w

Answer 1

http://msdn.microsoft.com/en-us/library/aa365247%28VS.85%29.aspx#paths

Apparently, \?? is a short form for \Global?? according to this article:

In NT naming convention, \Global?? can also be called \?? to shorten the access.