This letter of intepretation explains it much better. The distance (in miles or time) between co-domiciles can be standardized, for each situation! Not a general, across the board, definition of acceptance. It was about a pilot having to work from two locations, ie, fly out of one, return at another, now needing to commute home.
It is not a standard generalized distance you can put your finger for any specific situation. It is also NOT about a pilot who has one work location, and the certificate holder not starting you and ending you at the same location. If our helicotper breaks down in one location, and you have to drive a rental car, or take a bus, cab, train, another airplane back to get you to your domicile (your base), that is not local in character, and is not to be counted as part of your required rest.
Drawing a 50, 75, or 100 mile circle around your base is not IAW the definition or scope of "local in character"!