[Fsfe-uk] Licence?

[Anne-Marie MAHFOUF]

Hi,

I have a free licence-related question for you.
At the KDE-Edu project, we release our programs under the GPL.
We now have some common data that we want to make available (XML-based files 
and text files). These data will be used by several applications. I 
understand that this data must not come from proprietary books but must be 
created by the author. Is that right?
And what licence would tbe best for these files? 

Thanks for your help in that matter!

Anne-Marie