"Clyde Gill" wrote:

I think a split is 187 mls.

You are "legally" correct (at least in the U.S.), because that is how it
appears in the BATF regulations. The BATF formerly recognized 16 bottle
sizes for domestic American wine and 27 sizes for imports. That ended on
January 1, 1975, when metric sizing was introduced, becoming mandatory on
January 1, 1979. Except for “magnum,” the names of the sizes are not allowed
to appear on the label.

New size Capacity Old size
Miniature 100 mL miniature
Small 187 mL split
Medium 375 mL tenth
Regular 750 mL fifth
Large 1 liter quart
Magnum 1.5 liter magnum
Extra Large 3 liter jeroboam