There were several filmings of the censuses (redone when they started putting them on fiche as well as film). Brian retranscribed the IOM censuses from more recent PRO fiche after he found errors in his original transcripts from film. His page numbers sometimes differ from those given on Ancestry, so I've found the easiest way to use his refs post-1841 is to fill in the first two (Piece and Folio) under "Census" at the bottom of the Search page, as well as Residence: Isle of Man, and the Gender and Birth Year (+/- 2 or 5 years) and fill in nothing else! Including no names, because the Ancestry index is so often wrong.

Sue