AVA features a fairly unique and in depth clan system. For example, In AVA, clans have to actually earn clan marks/symbols.
As always, there is a leader of the clan. Clan leaders will automatically be the clan creator obviously, however, it is possible to appoint a new leader via Aeria's website.
Clans also have a squad system. These squads are divided into Alpha, Bravo and so forth. Only the clan leader can appoint members as well as the leaders to squads.
When a clan is first created, there is a limit of 24 members and is at the level of 'platoon.' To increase the maximum number of members, the clan must vs other clans to earn points. Meeting the required amount of points will 'level up' the clan and will thus allow more players to join your clan.
As your clan ranks higher into the leaderboards of ijji's website, your clan will be placed into divisions. 1st division for example, is for clans which are at the top of the leaderboards. Earning better divisions will also unlock special items and weapons in the shop such as the DSR-1 Dragon or the AWM Tiger.