+ The date in the copyright notice is not necessarily an indication of
when copyright in all the material in the work will expire. Some of the
material may already be in the public domain, and some parts of the
work may expire sooner than others.

+ Even if some of the material in the derivative work is in the public
domain and free for use, this does not mean that the "new" material
added to it can be used without permission from the owner of copyright
in the derivative work. It may be necessary to compare editions to
determine what is free to use and what is not.

+ Ownership of rights in the material included in a derivative work and
in the preexisting work upon which it may be based may differ, and
permission obtained from the owners of certain parts of the work may
not authorize the use of other parts.


THE NAME IN THE COPYRIGHT NOTICE

Under the copyright statute in effect before 1978, the notice was
required to include "the name of the copyright proprietor." The present
act requires that the notice include "the name of the owner of copyright
in the work, or an abbreviation by which the name can be recognized, or a
generally known alternative designation of the owner." The name in the
notice (sometimes in combination with the other statements on the copy,
records, disk, tape, container, or label) often gives persons wishing to
use the work the information needed to identify the owner from whom
licenses or permission can be sought. In other cases, the name provides a
starting point for a search in the Copyright Office records or catalogs,