127 has been very popular in the past and within 127 you had several formats like 4x4, 4x3 and some other odd sizes.
They were generaly smaller than the 120's and were amateur camera's.
Kodak made quite a few camera's and Rollei had their 4x4 in grey and later in black.
Putting a stamp on a camera is sometimes dificult and the "stamp" depends again on the starting point.
If you go by film size you would have Minox, 16mm, 110, 126, Bantam, 135/APS, 127, 120/220 and the 6xx formats, the 116/616, sheetfilm and plate camera's.
And the diskformat made in at least two diferent periods.
On the other hand you can make a devision in box, folder, RF, SLR, TLR, field, TC, panoramic, stereo and so on.
And you have your cross-overs aswell: a Nikon F is a SLR, but a Hassie too.
Maybe that is what makes camera collecting so interesting.
35mm motion picture film was the first film used in still camera's, in the 70's there were quite a few 16mm still camera's by Minolta, Edixa and many others to cater for a market that wanted smaller camera's.
110 was a time popular untill the people that used them found the limitations of the film size and inherent grain and went to the next generation of temporairy formats, despite camera's like the Asahi Pentax SLR 110.
Back in the 70's I predicted that a few formats would survive: 135, 120/220 and sheetfilm, film sizes used by the pro's.
I have come close to it at age 56.
Peter