Username restrictions (chars, length) - conventions?

[Ralf Gesel|ensetter <rgx@gmx.de>]

Hi there,

at the moment, newly created user names are restricted by wlus to
- 8 characters of length
- only alphanumeric characters 

Schools that migrate from an existing system also wish to move their 
naming conventions. Hence there are severe suggestions to loosen the 
described restrictions. Now the argue is about what should be the new 
limits:

As opposed to libc-5, libc-6 allows usernames up to 32 (i.e. 31 + \0)
Others say: Either have a limit of 8 or no limit at all!

How about underscore ("_"), dash ("-") and dot (".")? Within email 
addresses, each of those are quite common. I do need the dash only.

Thanks for contributing
Regards
Ralf