The Lotus team was rebranded Caterham (the current Lotus team is a rebranded Renault) while Virgin was rebranded Marussia. HRT was disbanded at the end of the 2011 season, leaving the current 11-team arrangement.
Any interested parties will need to submit an application by February 10, 2014. A decision will be made by February 28.
There will be a rigorous due diligence process where applicants will need to prove they have the ability and resources to run a team for the foreseeable future as well as prove they have the ability to raise and maintain sufficient funding to compete at a competitive level.
Of course, the long-term interests of the sport will also determine which applicant is finally selected.