'Sneaky beaky' is a term for the UKSF, although if the guy is RM and 'SF' more likely he helps the blokes who get wet on a regular basis, rather than the hooligans from Hereford.
And also depends how general your being with the term 'UKSF' since Pathfinders and SFSG get issued L119a1's.
Zak, if the guy is 19 that means he's been able to 'fight' for his country for 1 year (have to be 18) can't see as he would be eligible for UKSF yet? Thought you had to do a couple years service first?