general copyright question

[Saaa]

A lot of open source projects (on dsource) use this clause in their 
copyright notice:

...
Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
...

What exactly does it mean for a binary program to reproduce a copyright?

What should be written in the documentation?
Something like:
readme.txt [
.. documentation ..

??

< insert copyright from X> ]

and what if there is no documentation?