[Classweb-users] American folk painting number

[Koontz, Sylvia]

The various century divisions under "United States" each have class numbers for both general works and special aspects or movements (e.g. ND207 and ND207.5, in the Colonial period), but plain old United States only has the "general" number, ND205.
I have seen the number ND205.5.P47 used by LC and others for works about American folk painting that cover multiple centuries, however ND205.5 doesn't appear in ClassWeb. Is it no longer valid? Can ND205.5 be added to the schedule?
Thanks,
Sylvia Koontz
N.C. School of the Arts