The Full Form of SLF is Stiff Little Fingers.

Stiff Little Fingers are a punk rock band from Belfast, Northern Ireland. They formed in 1977, at the height of the Troubles. They started out as a schoolboy band called Highway Star (named after the Deep Purple song), doing rock covers, until they discovered punk. They split up after six years and four albums, although they reformed five years later, in 1987. Despite major personnel changes, they are still touring and recording. In 2014, the band released their tenth studio album and a world tour followed its release. Jake Burns, their lead singer, is the only member to have been with the band during all its incarnations, but in March 2006, original bass guitarist Ali McMordie rejoined them following the departure of The Jam bass player Bruce Foxton after fifteen years.