usually i see that in guitar tab books, but above the notes and tablature where they give you chords and strumming patterns...when you look at the beginning of the song they have chords used in it with chord boxes (usually above the title of the song) and if they have a C chord in it, then have a C power chord they'll just call it C (for the straight chord) and CII (for the power chord)...hopefully i explained it right for ya