1926 Unc issue (Negro League)

[Exhibitman]

I don't think it is a term of art like "T card" but I've always used the term to differentiate between a real photo postcard, a real photo card, a card made by some printing process, and a photo. I'd label the Frederick Foto cards as "photo cards": they are real photo cards, as opposed to halftone print, litho, etc. This is a real photo but also a postcard, hence real photo postcard (RPPC):



Simple enough. And this is a photo that is card-sized:



Very similar to your NL items, which is why I am hesitant to label them cards rather than photos.

It can get confused. I know of several such sets in the boxing arena that were made both as RPPCs and as photo cards: a set issued by IFS that was for the Dempsey-Willard fight in 1919:



if it has a PC back it is a RPPC, if not it is a photo card.

There are tons of "photo cards" from prewar entertainment, usually made by studios to send to fans. This Dempsey was made to promote his film:



Here are a favorite pair of mine: