WE 334A Subset

[poplar1]

I think that a hand telephone desk set (B1 or D1) with 3-conductor mounting cord is a 102. The early catalogs show B1A (manual), B1B (dial), D1A (manual), and D1B (dial) for a B1 or D1 handset mounting + E1-type handset + cords + dial or apparatus blank.

A B1 or D1 mtg. + cords including a 4-conductor mtg. cord + handset + dial or blank = a "202", regardless of whether its intended use was with a sidetone subset (584A, 534A, 295A, 315H, 300K, 334A--with the black conductor taped or stored on the subset end),  or with an anti-sidetone subset (684A,634A, 434A, 495, 415, or 400K). I'm guessing that by mid-30s all hand telephone sets with D1 mounting were equipped with 4-conductor D4S or D4U mtg. cords.

[TelePlay]

That makes sense. I imagine they would have "run out" of 3 conductor cords at some point and were forced to use the "new" 4 conductor cords for side tone hardware.