s:508:"Despite the similarity in names, this module is not intended to be equivalent to [[Special:PrefixIndex]]; for that, see <kbd>[[Special:ApiHelp/query+allpages|action=query&list=allpages]]</kbd> with the <kbd>apprefix</kbd> parameter. The purpose of this module is similar to <kbd>[[Special:ApiHelp/opensearch|action=opensearch]]</kbd>: to take user input and provide the best-matching titles. Depending on the search engine backend, this might include typo correction, redirect avoidance, or other heuristics.";