publishing a codeigniter application under the GNU GPL license

[eluser]Unknown[/eluser]
Hi there.

I've created a solution using codeigniter. Now I want to share my code using the GNU GPL license. I'm reading their page located at: http://www.gnu.org/licenses/gpl-howto.html

This might be a silly question but when they say I need to add a copyright information at the top of each code file, I am assuming I would only need to do this for my files... and not for the files included in the CI framework.
Is this correct?

Thanks.