The standard protocol for this sort of thing is to use the NATO phoenetic alphabet for letters. Sierra Golf one zero zero zero zero zero zero seven one two zero alpha dash november bravo. Note that British English speakers have a tendency to say 'double ----" or 'triple -----" when there are two or three identical numbers together in a series. For example : 488329777 - four double eight three two nine triple seven, In my experience, American English speakers find this confusing, so avoid using it unless you are sure your listener is comfortable with this form of expression.

There are probably a few ways to do it. If I was talking to someone on the phone, for the example you gave, the safest way I can think of is: S for Sally G for Goat 1 0 (pronounced as "zero" would be clearer than pronounced as "oh") 0 0 0 0 7 1 2 0 A for Apple - (usually pronounced as "hyphen" or "dash") N for Nelly ... literally spoken as above B for Bob

I'm not sure exactly what you mean. Would you provide some examples?