Reserved characters for file names

[Frans Englich]

Hello, 

What are the character ranges file names in XDG specifications must stay 
within, in order to work in scenarios relavant for XDG?

Perhaps characters can be divided into "forbidden" and "not recommended". For 
example, colon(":"), IIRC, is reserved on Windows.

I believe this subject have been discussed before, but I couldn't find it in 
the archives.


Thanks in advance,

		Frans