To start an expansion one must first have five animations done, in order for their expansion work to be accepted by the Expansion Acceptance Team. Their ideas or progress of their expansions should follow special rules to prevent moveset abuse. Expansions should be first approved by an Expansion Acceptation Team member and then coded in Flash by one of the devs so it could be playable on Super Smash Flash 2.
There is also a trash can where deleted expansions go if someone does not follow the rules, or if they create an expansion of a character that is not yet confirmed to be in SSF2.
There has been a total of four Expansion Forums (not counting the SSF2 Designer's League Community), and all but the current one have been closed due to the fact that the forums were rarely updated, most of its users being disrespectful, incomplete projects, etc.
The first Expansion Forums were opened around mid-2008 as Cleod9 wanted a separate forum for expansion characters to differentiate from his own website. Tredog777 (also known as Tredog), as well as SSF2 dev <Na> Suliboy and Expansion Veteran ShadowKirby (also known as SK), managed the forum. The forum soon adopted a quality clearance for expansions from a team of members known as the EAT, Expansion Acception Team, a format still used in all later forums to date. While the forum was a success, it was experiencing some downtime during it's opening few months, so SSF2 dev ItsameSMB opened his own forum called the SSF2 Designer's League Community.
Essentially this forum was a replacement for Tredog's forum during its downtime, and although some people joined, it remained relatively inactive. There is some debate as to if this site actually counts as an official Expansion Forum, not only does it bare a different title but it was created solely as a temporary forum until Tredog could regain control of his current site. Regardless, Tredog soon did open up his forum and it regained its normal functionality. This lasted for about a year, until one day the administration team decided it was fed up with the recent influx in incompetent members as well as the recent absence of Tredog, and decided to create a new forum of elite members. Those who found out about this idea thought it best to also make a new forum for the regular members as well, so on October 20, 2009 the official notice was sent out that everybody was moving to a new forum.
Those who didn't make the cut for the elite forum were directed to a new forum managed by Expansion Veteran SC, and the elite members were given a secret link to the Uncut Expansion Forums, managed by <Na>Suliboy. SC's new forum was often criticized for being too hard on new members, and seeing how nearly everyone with a higher position than member was also part of Uncut, it was left fairly unnoticed as the elite members where used to tough criticism and flaming during their first days on the original Expansion Forums. This mattered very little though, as SC encountered some difficulty with his website host, leaving the forum down indefinitely. With no other place to go, Uncut opened its doors for all members, not just the elite.
Uncut served its purpose, but soon it became just like Tredog's forum, overrun with unruly members. Suli tried to tighten the administration in order to alleviate the issue, but the members responded with anger and lost trust in the forums altogether. Seeing that the problem was only going to escalate, the SSF2 devs decided it was time to open another forum run only by devs in order to keep the members under control. It was opened on July 2, 2010 by SSF2 dev Geno and administrated by <Na>Suliboy. This new site has officially been titled the SSF2 Official Expansion Forums, and was the most current expansion forum.
Although the website had many competent members and was doing seemingly well, the McLeodgaming website decided to disaffiliate itself with the website seeing as it wasn't being run by members of the dev team. Despite stating that this wasn't a bad decision, many of the members of the Expansion Forums took this information to heart, perceiving it is abandonment and decided to make their own game, "Astrocops" but the project went nowhere and the forums were eventially deleted.
List of current Expansion Forum Staff