Pete031 --
The MSOSG includes much of the logistics support for MARSOC and provides many of the same functions as a Headquarters and Service Battalion. It has a fairly extensive motor pool and medical section and provides admin and annual training support for personnel assigned to the General and Special Staff sections. (For example, all Marines are required to complete a Physical Fitness Test twice a year and qualify with their standard T/O weapon annually -- in addition to the range of EO, ATFP, Security and similar annual training requirements common throughout DoD.)
In a sense the MSOSG fills the Combat Service Support role of the Marine Air Ground Task Force structure common throughout the Marine Corps.
(For those unfamiliar with the MAGTF -- pronounced "Mag Taff" -- concept, it is the basic task-organization model upon which Marine Corps doctrine is based. A MAGTF typically includes a Command Element, Ground Combat Element, Air/Aviation Combat Element and Combat Service Support Element. It can range in size from a Marine Expeditionary Force, with a Division as the GCE, Wing as the ACE and Marine Logistics Group as the CSSE to an approximately Battalion-sized Special Purpose MAGTF. In each case, the MAGTF is tailored to the mission at hand.)
The MSOSG is unique from other Marine CSSE's in that it also includes communications, intelligence, military working dog, EOD and other capabilities that can be drawn upon to form "enabler detachments" to supplment MARSOC Companies or Teams.
Semper Fidelis!
Maj. Gilmore