Joe T,
The 4S (or 1900) boxes I get from my wholesale house do not have any sort of marking around the threaded 10/32 hole in them... & they are UL Listed.. As far as this falling under 110.3(B) The same box with or without the GR or GND stamp can be found by different manufacturers.. (Raco, I believe has the GR mark, the ones I use are Bowers & they dont).. I don't think this marking is integral to the "listing" of the box or else they'd all have it!..

On another note, Here's a question I asked in another thread... Joe, Please look at the following photo and tell me if I should be cited under 110.3(B) for mounting this outlet "ground-down"

[Linked Image]

The word "TOP" appearing here I believe is just as integral to a listing as the "GR" mark in a metal box [Linked Image]

JMHO

-Randy

PS.. Photo from: https://www.electrical-contractor.net/ubb/Forum5/HTML/000527.html

Edited to add the above link

[This message has been edited by Lostazhell (edited 05-25-2004).]