Have queried this before but it didn't get posted. How are posters classified? For example, Junior Member, Member and Senior Member - how do you get 'upgraded' to Member or Senior Member?

I believed it was on the number of posts and thought I saw a post which stated that you became a Member after you had posted 30 times but I have posted more than 30 and am still a Junior Member; I have seen members with over 100 posts and they are also Junior Members and also members with 100+ posts who are classified as Senior Members.

Would be good to know how posters are classified.