You will have to enter your punkbuster GUID into the teamwarefare site. I found these instructions on their site
-Working with PBGUID's
The following is a general guideline on "How to handle GUID issues"
1. How to locate your GUID and how to enter it in your profile?
* PBGUID's are required to be in your personal profile on TeamWafare for all Ladder and League participants. You can add your guid to your profile the following way:
* Open Battlefield, join a server (one with Punkbuster running), hit the "~" key and input /pb_plist in your console. Take note of the last 8 alphanumeric characters of the 32 alphanumeric characers displayed. This is your PBGUID. This is all you will need to input into your profile.
* Once you have captured your PBGUID go to Account Maintenance ---> Profile ---> Anti-Smurf In Game Identifiers ---> Add another ID. Add the last 8 alphanumeric characters of your GUID in the window there. If you have trouble doing this, clicking your name on your team roster page will bring you to your profile.
Also the ladder rules can be found here