Annotate Profile/Cant Alignment settings - Does the Cant Alignment Refer To The High Rail or the Low Rail?

Hi All

I have a question relating to the Annotate Profile/Cant Alignment settings.

I have annotated my profile and I have the following:-

The dotted line represents the centre axis, so for horizontal ealignment this would represent a Straight and for the Cant Alignment this would represent 0mm of Cant.

My question is this; does the cant alignment refer to the low rail or the high rail?, in this case the cant alignment is below the centre axis so does this refer to the low rail being low by 15mm or does it refer to the high rail being high by 15mm?

In project options I have set my cant to rotate about the inside rail.

An ideas?