Media markup system for content alteration in derivative works

A classification method and system for possible content alteration of a media work may include criteria regarding content that is feasible for alteration. Such criteria may be maintained in records that are accessible to an interested party. Some embodiments may include a record of primary authorization rights applicable to a possible content alteration. A further embodiment feature may include a record of secondary authorization rights applicable to substitute altered content incorporated in a derivative version. Various exemplary identifier markup schemes indicative of a location or category of an alterable media content component may be implemented for audio, visual, and audio/video alterable content.