by Tomasz Ostrowski on WordPress.org
With this plugin you can define a PCRE regular expression against which data entered
in XProfile fields will be matched.
For example:
%^(https?://)?([^ :/]{1,63}\.)+[^ :/.]{2,63}%iu/^1?[0-9]?[0-9]$//^+?[0-9 -]{7,45}$//^.{10,100}$/uYou can also configure a message to show when a field data does not validate.