MediaWiki:Apihelp-compare-extended-description
From MoodleDocs
A revision number, a page title, a page ID, text, or a relative reference for both "from" and "to" must be passed.
Note: You are currently viewing documentation for Moodle 3.1. Up-to-date documentation for the latest stable version of Moodle is probably available here: Apihelp-compare-extended-description.