Copyright and Fair Use

There are three reasons a work may be in the public domain:

1. Copyright protection has expired.
2. The work is ineligible for protection.
3. The work was placed in the public domain.

Most federal documents and images are in the public domain, as long as they were produced during the normal course of business and the federal government has not contracted with an outside provider.

Source (used with permission from the author):

Copyright Compliance Made Simple: Six Rules for Course Design by Linda K. Enhagen