Negodki: The term is used for both the 187 ml bottle and the 375 ml bottle
(as you can verify with an internet search for "split wine bottle").

Clyde: You can find just about whatever you want on the internet. Doesn't
mean it's correct.

Negodki: No, but it DOES prove that the term IS used (correctly or
incorrectly) for both the 187 ml and 375 ml bottles, which is what I stated.
I also posted a followup which admitted that the definition in the BATF regs
corresponds with yours. That doesn't negate the fact that the term is used
for both bottle sizes. And since usage of a word defines its accepted
meaning, neither definition is correct or incorrect.

Negodki: It originally applied to the 375 ml bottle, and derived from "Let's
split a bottle".

Clyde: Sounds catchy, but I don't think it's true.

Negodki: No? Then what is the etymology of the term in this context?

Negodki: The 187 ml bottle is a relatively new creation.

Clyde: What makes you think that?

Negodki: History?