Postmark ID Please

Help! I can't find the proper name for this type of US postmark that has such names a Grand Central Annex, Church Street Annex, Madison Square Station etc. I assume these are the locations of the post office.



There's got to be a word for these. Can you help?

I've always referred to them as machine cancels with slogans (however, instead of the slogan advertising some program or service, it merely refers to the "Station" or "Annex" in New York where the postmark originated.)

I've seen them used for several larger cities such as Chicago, New York, Boston, etc.

Actually, I find those postmarks especially interesting because of the time stamp. You'd never find a postmark today that showed a 3:30 AM time stamp in a postmark. Just goes to show how efficiently the mail was processed even back in the 1940s.

I simply classify them as machine cancels with slogan killers. That particular cancel was from International Postal Supply Model D26.

This thread prompted me to pull out my New York City Station & Annex Slogan Cancels from 1940-41. I have eight (8) different ones. I wonder how many different ones were used in New York City? Any ideas?