• This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn more.

XF 1.1 Need code format to accept PayPal order numbers but no other


Well-known member
I've got a field created on the Preferences page in the admin area that requires the user to enter an order number that matches the format of PayPal order numbers but no other.

Could someone please let me know what that is at your earliest convenience? A spambot has found my site and I'm getting flooded with people just putting the string
in the Order Number field.

MANY thanks!


Well-known member
This is an example:

I'm not sure all PayPal orders follow that exact combination of alphanumerics but we can start there since the spambot is at this point just filling that field with:


XenForo moderator
Staff member
Well you can use regex to limit to A to Z and numbers, like so ^[A-Z0-9]+$ but it won't stop the bots once they learn the new pattern.