The Form of the Short User Name

Question

Hello,
I have a quick question about setting up accounts, notably about user names, and specifically about the form of the short user name (the one used for the home folder).
I’m going to have to set up a computer with Snow Leopard for someone who knows even less about this stuff than me, so I’d like to do it properly from the start in order to avoid any problems, either immediately or down the road.
In Leopard (10.5), Apple clearly says that the short user name should contain only lower-case letters (http://support.apple.com/kb/HT1428). For example, if your full name is “Charlie Brown”, or just “Charlie”, then presumably your short user name would be “charliebrown”, or just “charlie”.
However, I’ve read that Snow Leopard now supports short user names with capital letters. So, if your full name is “Charlie”, your short user name, and the name of your home folder, can also be “Charlie” (with a capital “C”). This change is apparently not documented by Apple (as mentioned here:
http://www.tuaw.com/2010/01/02/ssh-and-the-case-sensitive-username-in-snow-leopa rd),
and there is one previous allusion to it on these forums (here: http://discussions.info.apple.com/thread.jspa?messageID=10722806).
The use of short user names with lower case letters seems to have been the rule for a long time. I’ve read that this practice is attributed to some kind of Unix convention, although I’ve no idea if this is true (and I’ve even less of an idea of the reasons why Unix might prefer just the lower case to the regular combination of upper and lower case). Anyway, the thing is that I’ve read of problems being created by using capital letters in the short user name, for example when restoring from Time machine (see the last comment on this page:
http://discussions.apple.com/thread.jspa?threadID=2266359&tstart=225), and so I’m asking myself two questions:
(1) Is the use of capital letters in the short user name definitely supported now by Snow Leopard?
And, more importantly, (2) is there is a “best practice” in this regard? In other words, is the use of lower-case letters in the short user name really some kind of a convention, and is this the advisable way to set up a machine? Or does it not matter at all which case one uses in the name?
As I mentioned, I’d simply like to get things straight from the start in order to avoid future problems, since I know that changing the short user name is not particularly advised.
Thanks to anyone who might be able to shed some light on this detail to help me understand what is going on here.
Best regards,
Stephen

Answer 1

Thank you, Kappy, for your quick and helpful reply to my (admittedly) not very quick question!
It strikes me as odd that Apple would appear to make the use of both lower- and upper-case letters possible in the short user-name, leaving the possibility that upper-case letters might lead to some problems/conflicts down the line. It would be helpful if they'd provide some explanation about this. Anyway, as I said, I'm very far from being an expert in all this, and appreciate that people like yourself on these
forums are willing to provide helpful feedback.
Best regards,
Stephen