With this plugin you can define a PCRE regular expression against which data entered in XProfile fields will be matched. For example: check webpage field for a correct(-ish) URL or domain name: %^(https?://)?([^ :/]{1,63}\.)+[^ :/.]{2,63}%iu check age field for a sane(-ish) value (0-199): /^1?[0-9]?[0-9]$/ check phone field for a sane(-ish) value: /^+?[0-9 -]{7,45}$/ check any field for a minimum and maksimum length: /^.{10,100}$/u You can also configure a message to show when a field data does not validate.