GFDL is the standard abbreviation for the GNU Free Documentation License an open content license. There is a vast GFDL Corpus under this license, consisting of over one million articles in over fifty languages. Its naming conventions are dominant over all others on the web and in wikis in particular, and there is no choice but to adopt them. Unfortunately some tikiwiki flaws prevent them from being adopted letter for letter, comma for comma, apostrophe for apostrophe. Accordingly we refer to such articles and can't easily just import them as we could if we were using GetWiki technology.

That technology is under CC-nc-sa license which is an alternative to GFDL, part of the Creative Commons suite, and is probably the best for Living Platform open content. Code should probably be under GPL or some new Creative Commons variant that could forbid military or eco-destroying use - failing that the CC-nc-sa license is also suitable for code, while the GFDL isn't.