In R-logic dialog, you can set the number of the R-sites to be occupied in Occurrence field. If the RestH condition is set for an R-group, that means that the hit molecules do not contain ligands on that atom other than hydrogen or those specified as R-group.
R-logic dialog is available via Empty space, R-group definition context menu and also by right-clicking on R-group label in the scaffold structure.
Valid values for Occurrence:
Exact number, e.g. 2
Less than (>) + number, e.g. <4
Greater than (<) + number, e.g. >1
Range, e.g. 2-3
R-group representation and editing options