widget anchoring in PhAB

I have noticed than since 6.3.0, there is no relative widget anchoring !!!
In 6.2.1, the ‘Anchor Flags’ resource had several …_ANCHORED_RELATIVE
options.
In 6.3, these seem to have been removed!

The …_RELATIVE #defines such as Pt_LEFT_ANCHORED_RELATIVE are still in
PtWidget.h, but appear to have no effect when used in PtSetResource(…)

Just curious as to why these were removed, and if there is some way they can
still be used in 6.3.

Regards,
Robert Duncan