I said it has nothing to do with mods, and I was talking about rank :P BTW, they're just members with more power, and any that I've run into are fairly nice. Just don't break the rules, and they shouldn't be scaring you.
Okay, this is how you become a linking member:
1) make a website
2) have it somehow involve bettas
3) link to bettafish.com or tropicalfishkeeping.com
4) PM a mod and ask them about becoming a linking member, or try searching it.
It's not something I personally know outside of this, because I don't have any websites.