To clarify, there is no "FMS" approach to SFO, but an aircraft with a properly certified FMS can use it to fly any of the eleven RNAV approaches into that airport (see the AIM Section 1-2-1 paragraph 4). One would, however, expect a controller following the book phraseology to clear the aircraft for either the "RNAV GPS Runway 28R" or the "RNAV RNP Runway 28R" approach. Note further than none of our light GA GPS boxes (Garmin 430, KLN-94, etc) are approved for that RNP approach, but the airliner FMS's probably are. For more on RNP, see the AIM Section 1-2-2.