Standing for "Special Operations Training Group," it is a United States Marine Corps unit generally associated with certifying the Marine Expeditionary Unit (MEU) Special Operations Capable (SOC). There is one SOTG unit per Marine Expeditionary Force (MEF).
On top of certifying the various MEUs SOC, the unit also provides a variety of special operations training ranging from CQB
to scout swimmers to spie rigging and much much more.
There are also various other definitions of the acronym (more than likely created by the Marines in the unit itself). These include but are not limited to:
SOTG - Society Of Tough Guys
SOTG - Special Olympics Training Group
SOTG - Sorry Our Training's Gay