The way I see it, if you have donated, you are listed as such. Starting in 2014, that donation status was a bit changed. stop there. The donation from now on enables you to access several areas within the site that others cannot ( selling areas). Some folks are sponsors and have some business interest in the site.
Some members were here from day one (or two maybe) and are designated as Charter members.
At least one member, because we all love her so much, is designated as a Chatter member, to make her unique ! Earlier on, she earned that title with her devotion to the site.
I guess that leaves the bosses.
ChuckC