I worked on the supplemental materials for the DVD of film XYZ. Can I add my credit to the film?
If you only worked or appeared in the special features/extras of a DVD you are not eligible to be included in the cast/crew listing of the film, unless your name is included in the on-screen credits of the theatrical version.
In other words, if you worked on "The Making of Film XYZ" and your name is included in the on-screen credits of the theatrical version of "Film XYZ", you are eligible to be listed on the page for "Film XYZ" in the database. But if you did not receive on-screen credit in the film itself we cannot list you. Please note that this type of credit is very rare.
However in many cases, supplemental materials like 'making of' documentaries qualify for their own title listing in the database. See for example: