It probably hasn't loaded for you yet.
And a PC supporter is someone who has donated to PC, and whatever the Tier is, is depended on the amount you've donated to PC. The higher you donate, the higher your Tier is. (1 being the lowest and 6 being the highest)
Donating as you know, means giving money to the community aka PC, as a way to help keep PC running. For more information, visit this link.