Templates have a wide range of uses on Memory Alpha, and are grouped into five major categories: * Message templates * Navigational templates * Sidebar templates * Meta templates . There are a number of pages in the "Memory Alpha" namespace that exhibit a very high rate of turnover; these include the pages for deletion , featured article nominations , the main page, and others. In these cases, it is beneficial to include text that is not likely to be changed in a separate template, because it helps conserve disk space by not saving the same text over and over again.