The lineset schedule is the description of the pieces hung on the fly rail; each rope is a "lineset". It usually lists # of lineset, distance from proscenium, and description of the piece, i.e., Wall Drop, Electric #2, Border, Hanging Legs, etc.
I can't help you specifically with "track type - unibeam". I suspect it has something to do with the material "unibeam" that the hanging pieces are attached to - are they sliding masking flats???