Unauthorized

Unauthorized works are stories about Tarzan which were published without the approval of Edgar Rice Burroughs, Inc. (ERB).

Publication before the original Tarzan of the Apes story entered the public domain would violate ERB copyrights, unless it was reasonable fair use (such as parody).

Later unauthorized publications would still violate ERB copyrights if story elements—characters, events, locations, etc.—introduced in still-protected ERB works were used.

Regardless, use of certain key terms (such as the name "Tarzan") would be a trademark violation since ERB continues to use and maintain those trademarks.