Usually when it's at or near the end of a line like that the g or m symbol is an end-of-section marker, but it does seem to be used here as a page marker, as you pointed out.
I see the k and g and m symbols in practically every Latin-based manuscript to mark section beginnings, sometimes section ends, and also as ligatures, but I can't remember seeing g/m being specifically used as a page marker in other manuscripts. I'll pay more attention in the future and see if this happens elsewhere.
I see the k and g and m symbols in practically every Latin-based manuscript to mark section beginnings, sometimes section ends, and also as ligatures, but I can't remember seeing g/m being specifically used as a page marker in other manuscripts. I'll pay more attention in the future and see if this happens elsewhere.