Username Regular Expression PCRE Help
 

i am presently using: ^[A-Z0-9 ]+$
which means: Alphanumeric characters including space

Now, i want an expression where besides above condition, nobody is allowed to register with numeric only username.

e.g.

username:
abcdef is perfectly fine!
abc123 is perfectly fine!

but username:
123456 should not be allowed!

What would be the regular expression?

Thanks