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IP Protection and Copyleft

Options for distribution and protection of Core Practice:

GNU FDL

http://www.gnu.org/licenses/licenses.html#TOCFDL
allows modification

Creative Commons

http://creativecommons.org/licenses/by-sa/2.5/
range of different licences depending on modification etc

Waived copyright

Effectively just an informal version of either of the above licences
E.g. FITS http://www.becta.org.uk/tsas/docs/fits_fits.pdf