D M S Z On Corners Of German Bohmen Stamp?

Hello,
Can anyone tell me what the four letters on each corner signifies and also, Is it a German stamp, Bohmen, and I've seen online where it was mentioned as a GeneralGouvernment stamp?
Thank you!
SueStamps

D and M presumably stand for Dienstmarke, the C and Z would then be the Czech equivalent of that. It's one of a series of 12 officials issued in 1943, you have the highest denomination.

It is from the German occupied Czechoslovakia minus Slovakia and the Sudeten area, full name Protectorate of Bohemia and Moravia. The Generalgouvernement was the name for the rump area that was left of Poland after German annexation of the Polish border areas.

Hope that helps.

Good Golly, I'm impressed!
Thank you for that information!!

It's listed in the Scott Catalog under Czechoslovakia, but Bohemia & Moravia (B&M) is often collected as part of a German-area collection as well. The Nazis issued stamps for most of the territories they occupied, but B&M has more than most - a couple hundred stamps or so, including commemoratives, semi-postals, officials, etc. Most occupied territories (other than Poland/Generalgouvernement, which also had a lot) had a handful of definitives issued and that was it.