The crank and not the bottom bracket shell determines the proper BB sizing.

Almost all road and track frames have a 68mm shell.

The difference in Phil (and other) bottom bracket sizes refers to the length of the spindle, or the crank axle.

For example, in order for the chain ring to give a perfect 42mm (or 44mm) chain line, the bottom bracket spindle length/width and the amount of "dish" in the crank spider have to work together to produce that chain line.

Different crank spiders have differing amounts of dish, and therefore require different length spindles in order to put the chain ring in the proper relationship to the cog.

Look up your crank set on the internet, and someone will say what bottom bracket spindle length will best work with that crank.

I've seen spindles from 103mm to 110.5mm, and it would not surprise me to learn of cranks requiring a longer or shorter spindle.

Happily, the Phil bottom bracket cups allow 5mm of movement left or right, and so Phil lists both a 108mm spindle and a 110.5mm spindle as workable with a Sugino 75 crank.

Talking to the folks at Phil, though, they specify 110.5mm as the correct spindle for the Sugino 75 crank.