Question

Allowing them to use the symbols at the @#$%^&*(),.? for registration?
My site users for register site use symbols @#$%^&*(),.?. After i share facebook or social network link dont work because user use for login symbol .. ()

Is it possible to prevent a user so that it can only be used in the login only characters:
abcdefghijklmnopqrstuvxyz0123456789

Comments

Yes it is very possible.

The theory is this.

1. First use regex or any other means to see if the username name field contains any of the following characters @#$%^&*(),.? during registration

2. if any of such charcters are found, halt the registration and send back a message to user that such characters are reserved for system use therefore he should not enter such characters. in otherwords, he/she can use [A-Za-z][0-9]

3. If such characters are not found, just continue with registration.
The problem is that I am not very familiar with q2a functions so I cant tell you which specific code to modify.

Answer 1

filter_handle will be useful for you. Make the process of Vanbells in this function.