In certain cases, all editors are allowed to submit modifications, but review is required for some editors, depending on certain conditions. For example, the German Wikipedia maintains "stable versions" of articles[77] which have passed certain reviews. Following protracted trials and community discussion, the English Wikipedia introduced the "pending changes" system in December 2012.[78] Under this system, new and unregistered users' edits to certain controversial or vandalism-prone articles are reviewed by established users before they are published.[79]
