Ukrainian Cancel Abbreviation Mystery

Some time ago I received a nice postcard. Reviewing it, I am mystified by the letters "TsOP" in the cancel.
It is not, I think, the region (woblast) where the town Sumy is situated.
Hoping for some ideas, I thank you all!
Heinrich

Could it be an abbreviation for some sort of postal facility where the mail is collected, sorted and canceled? Something like "Sumy distribution center" or "Sumy sorting center". Just a guess on my part.

Robert

Hi trainwreck.
my wife had an excellent idea: The "Ts" could be the Latin equivalent of the Cyrillic letter #1094; and therefore be the abbreviation the of word #1094;#1077;#1085;#1090;#1088; (=center).
Combined with your idea above, the four letters probably are the abbreviation of something like:
Center for the organization of the post.
I used the goo** translater .... organization and Post in Ukrainian begin with the same letters as the English words.

Thank you!
Heinrich

More ideas are still welcome.

It is the word POST in reverse...