Canter infeed slew and skew positions the log to the correct position, in relation to the canter side heads.

If the log "sawing" centreline is skewed to the canter centreline in the infeed, the infeed skews and offsets to align the log centreline with the canter centreline.  The infeed then slews (moves sideways) as the log is processed through the side heads.
If the log is parallel to the canter heads but offset from the canter centreline, the infeed offsets only to align the log to the side heads.

Used on double length infeeds (DLI), optimized length infeeds (OLI) and single length infeeds (SLI).