I would create a new access right "Allow Only to OK GR"

New acces right is independent on standard access right to Register GR,
as standard access rights to registers (in your example kAccessLevelReadOnly) are controlled by C in standard.
There is no need to disable update of GR register by standard access to GR.

New acces right will be checked only on Window Actions:

1. Window Action PUDClassButtonFlags, Window Action PULClassButtonFlags. As an example check IVDClassButtonFlags in standard hal.
2. Window Action PUDClassActiveEditField and in such ButtonActions as PUDClassInclVATButtonAction,PUDClassExtraCostsCalculationButtonAction an etc.


/Nadezda 17.04.2017