How to stop Alphanumeric Registrations

[Veer]

Hello,

I need your help to only stop registrations with alphanumeric characters? and all other Characters should be allowed.

I tried Username Regular Expression option with ^[A-Z ]+$ - Characters from A-Z including space, but it is also restricting underscore ( _ ) and dash ( - ) I don't want to stop underscore, dash and dot for example:

User-n-Name - should be allowed
User_Name - should be allowed
User.Name - should be allowed


Thanks.

[Jake Bunce]

I think what you mean to say is that you want to allow only alphanumeric characters and some types of punctuation. The regex can be used to do this. But I don't have a regex to do exactly what you want. If no one else here is able to help then a google search might find a regex for you.