What does an equal sign with a circle around it mean?

What does an equal sign with a circle around it mean?
An equal sign within a circle is a the grant of a copyright license providing additional users the right to share, distribute and post only exact copies of the original work. Thus meaning no one can comp or alter the work whatsoever if republishing the image.

Source(s): http:/creativecommons.org/about/license

Allison Bricker