Default: The name states it, you are the default player, and you are new to to the server.
Resident: You have been with the server for at least thirty hours without offences, you must also have a forum account with the same name as your ingame name. If you have had previous bans or warnings, you must have played for at least sixty hours and have a forum account to be resident.
Donor: You have donated to Kreatious, which helps keep the server running. You must donate $5 or more to become donor - Donate at donate.php
Veteran: You have played long enough to earn the respect and trust of Kreatious players. Veterans are active community members, meaning: Go on Teamspeak, post on the forums, play in game, and help other players.
Veteran Donor: Combine the requirements of being a Donor and a Veteran.
Moderator: Extremely trust worthy and helpful players. Chosen by existing staff to help protect and manage the server.
Admin: Performs administrative duties such as server management and coding. It is extremely unlikely that anyone will ever be promoted to this rank.
Do not ask for promotion, it won't happen if you do.