G64 P- Q- naive cam tolerance setting

Hope this isn't a daft question with an obvious answer, but I'm not sure what the Q setting units are in G64 P- Q- .
To quote the LinuxCNC User Guide:-

G64 P- Q- it turns on the "naive cam detector"; when there are a series of linear XYZ feed moves at
the same feed rate that are less than Q- away from being collinear, they are collapsed into a single
linear move.

'less than Q- away from being collinear' ? Would that be an angle or a linear distance?

subtractive wrote:

'less than Q- away from being collinear' ? Would that be an angle or a linear distance?:

Linear AFAIK.