“ Protecting pages The wiki pages on most Wikimedia projects are designed to evolve forever. Typical examples are Wikipedia articles or Wikibooks study guides.
By contrast, Wikisource is a library of static texts that have already been published elsewhere. In many or most cases, these texts are not meant to change and evolve, and it would deeply hurt their integrity if they did! Therefore, Wikisource has adopted a policy of noting text quality and "protecting" pages from editing once they are thought to be correctly formatted and error-free. ”