Wikipedians attending or graduates of International Baccalaureate, most likely the IB Diploma Programme.
Add yourself by adding [[Category:International Baccalaureate Wikipedians|yourname]] to your user page, changing "yourname" to your actual user name.
Alternatively, you can add the following userbox to your page, which will automatically put you in the category. The code for that is ((User:SuperNova/userboxes/ib)).
| IB | This user is a graduate or student of the International Baccalaureate. |