Extensive analysis of the story of Votan appeared as commentary on the work of Antonio del Río by Paul Felix Cabrera in 1822.

The identifying material should include as many pieces as necessary to show the entire copyrightable content of the work, including the copyright notice if it appears on the work.

If you are redistributing or providing access to a work with the phrase "Project Gutenberg" associated with or appearing on the work, you must comply either with the requirements of paragraphs 1.

In general, this notice had to appear on the copyrighted work itself, but in the case of a "work of the fine arts", such as a painting, it could instead be inscribed "on the face of the substance on which [the work of art] shall be mounted".

As a compromise, the possibility was created to add a relatively unintrusive mark, the capital letter C within a circle, to appear on the work itself next to the artist's name, indicating the existence of a more elaborate copyright notice elsewhere that was still to be allowed to be placed on the mounting.