If you search the OSHA website for scissors lift, you'll find their interpretation. I'd have to go through my notes, but I think scissors lifts are under the scaffold regulations. (But I'm not sure what you mean by "manlift".) [See below]
02/23/2000 - Fall protection, training, inspection and design requirements of aerial lifts and scissor lifts/scaffolds.
and
07/21/1998 - Aerial lift regulations; fall protection for scissor lifts.
Joe