I believe he's referring to toe-in/toe-out as in tires on a car... a non-zero angle of the blade in reference to the front edge of the saw... in the axis that would cause the blade to be non-parallel with the guide rail.
does that make any sense? it's hard to describe without a drawing.
edit: There are some pictures here:
http://www.ozebiz.com.au/racetech/theory/align.html