Case sensitivity

Hi,

I am using the pattern:

^([a-z]{3,})+[0-9]*$

to force something like: “username123”

Basically, I want to ensure that the letters are all lowercase.

It seems however, that the above pattern DOES allow uppercase letters. So something like “USERNAME123” is accepted, when it shouldn’t (if I understand regex patterns correctly).

Is this intentional coding in the plugin or what can I change to enforce case sensitivity?

Thanks.