An interdepartmental committee that has overseen Project: LONG STAIR operations since 1977, when it was deemed that the US Military should no longer have sole jurisdiction.
BLACKLIST is comprised of 13 individuals appointed by the President. The membership of BLACKLIST is kept secret, though it is known that the Centers For Disease Control always has at least one representative. There is also a significant military presence to represent the interests of the military services who make up the vast majority of LONG STAIR personnel.
BLACKLIST does not involve itself in day-to-day management. Instead it sets operational directives, controls budgets and otherwise represents the President. While presidents can and have overridden BLACKLIST decisions, it is uncommon.
The change was made for a number of reasons, the most important of which was a lack of confidence in a purely military command following the disastrous Gnome King Revolt and the brief evacuation of all personnel to First Landing. The Church Committee revelations also fueled a new administration's desire to reign in "black operations." The diffusion of xenotech artifacts outside the military into other government branches contributed to a desire of those branches to direct future operations.
For security reasons it was decided that BLACKLIST would have no direct contact with LONG STAIR. They would instead be copied on all paperwork, reports and intercepts and base their decisions on that data. This controversial set-up was intended to 1) prevent outside nations from discovering the existence of The Basement, 2) prevent criminal corruption by insulating command from operations and 3) prevent metaphysical corruption, as there were widespread fears that hybridization could infect the chain of command (aka a RUNAWAY scenario).
While the current setup has worked for over 30 years, it is not without significant problems. The detached nature of oversight has lead to command frictions and morale problems. Even senior staff are frequently recorded using colorful vulgarities at great length to describe the BLACKLIST directives and members. The correct suspicion that the multiple overt and covert "security sensors" are used to spy on LONG STAIR personnel only add to these problems. Fortunately LONG STAIR remains unaware that the sheer mass of data precludes any detailed analysis of the "spycams."
It is unknown, but highly unlikely, that BLACKLIST is in anyway aware of SKULL ISLAND.