One other thing: most tunes have "standard" changes that are either the composer's original changes or those in the fake books. Often I and other posters submit chord charts with non-standard changes or with intros/outros/solo choruses, etc and we want other users to be aware that the harmony or the structure of the tune has been significantly changed. Thus, I post tunes that have been changed with something in the title (usually (k rev) or (k ver) for a revision or a version) to alert myself or someone else that the chart is "non-standard." In that way, a standard chord chart will not be replaced by a non-standard chart by accident. As Bob indicated, placing singers or soloists name in parentheses after a title for a specific performance is often done. All this to avoid confusion by other users of non-standard charts.