Gavin
The term MOTO refers to a type of handstamp used to date Money Orders in Canada.
In 1928, the post office issued two kinds of handstamps for use on Money Orders ( these handstamps were also used on mail as well). The money order stub shown below illustrates the two types:

1. MOOD (Money Order Office Datestamp)

MOODs (named by philatelist R.F. Narbone) are circular handstamps.
2. MOTO (Money Order Transfer Office)

MOTOs are rectangular handstamps.
In the 1950s, a third type of handstamp was produced,called MOON cancellations.
3. MOON (Money Order Office Number)
These rectangular handstamps include the number assigned to the post office.
MOONs were in use until 1973. The cover below shows a late usage of a MOON handstamp.


White Head, New Brunswick
Office Number X990
In 1973 a new handstamp was introduced which made the MOONs obsolete.
4. POCON (Post Office Computer Office Number)

Early POCONs were unframed rectangles.

And that's the story of MOODs, MOTOs, MOONs, and POCONs up to the 1970s.