[thelist] Rules for valid css class names

[Dave Merrill]

Can anyone point me to the rules for what constitutes a legal css class
name? The Class Selectors section of the w3 css21 spec doesn't say.

More specifically, can class names begin with a digit? I thought not, but I
can't put my finger on where I saw that. I've been given some code that uses
classes like this, and I'm wondering if it ought to be tweaked.

Dave Merrill