I have finished the first prototype of the archive format that I have been constructing over the past two months, and I have written a PDF file of the specifications. I am wishing to release it under the GNU Free Documentation License, Version 1.3, as I wish to ensure the entire format remains free, and also so the community can see it, make suggestions and spot errors in the documentation that I might have missed. Besides saying that it has been released under the GNU Free Documentation License, Version 1.3, and providing a link to the licence on the Free Software Foundation's website, is there anything else I need to do to ensure the licensing on the document is official? I'm kind of dreading the worst case scenario of someone taking the document, stripping the licence information from it and then claiming that I'm stealing from them. The archive format is designed for data that seldom changes, such as textures and audio clips in games, hence why I have posted here.

Short of making a trip to the patent office, there isn't really more you can do that sticking the license into your documents.