for use with Microdata.
* The HTML5 <mark> tag has been whitelisted.
* Added ParserCloned hook for when the Parser object is cloned.
+* Added AlternateEditPreview hook to allow extensions to replace the page
+ preview from the edit page.
+* Added EditPage::showStandardInputs:options hook to allow extensions to add
+ new fields to the "editOptions" area of the edit form.
=== Bug fixes in 1.21 ===
* (bug 40353) SpecialDoubleRedirect should support interwiki redirects.