There's a couple of buttons on the front panel (Variation 3 & 4) sub-labeled 'Mark A repeat' and Mark B delete' which I can't find any reference to in the manual. Maybe this is a Mark/Jump feature for the SMF playback? Puzzling...
Although Diki, if you look closely at the pic in the manual, it does say "MARKER", not mark...so maybe it is a midi file repeat marker.
Would not be the first time Roland left something out of a manual

Dennis