You might want to have a squiz of the Forum Userguide which is located in this section of the boards. An explanation of some of the ranking (& privileges) is taken from the Forum Userguide & outlined below.

Rank 1 - New/Inactive
This is the rank everyone starts with. You don't have access to some sections of the board, or the PM (private messages) system. You need to interact here a little first for us to be sure that you are a Transformers fan, and we will activate your full Basic membership.

Rank 3 - Basic Member
When someone has interacted here a little, or posted an introduction, it helps us see that they aren't a spammer/scammer, and they gain this ranking, which gains access to the Meets and Sales sections, plus the PM system.
Welcome to Ozformers.