Hi -- It's not required, but it's a very nice gesture! Also, it's a two-stage process. First go to the main lens list and secondly choose your lenses by checking the box next to the name. This puts the lenses on your personal lens list... less to scroll through when applying this data to photo uploads.
The main lens list is missing all Hasselblad and Rollei medium format lenses, also no swing-lens pano lenses. If you'll list your lenses here, I'll add them to the main list. Please do the best you can in using the full official name and camera mounts!