Forces of the City
From Destinypedia, the Destiny wiki
The Forces of the City (FOTC) is an organization tasked with the defense of the City on Earth it is mainly comprised of frames and non guardian military personnel. Equipment belonging to the FOTC, such as weapons or aircraft, are commonly labeled with the organization's acronym. All firearms in the FOTC's arsenal are heavily customizable.
The FOTC has made no appearance in the final version of Destiny.