* The <data>, <time>, <meta>, and <link> elements are allowed within WikiText
for use with Microdata.
* The HTML5 <mark> tag has been whitelisted.
+* Added ParserCloned hook for when the Parser object is cloned.
=== Bug fixes in 1.21 ===
* (bug 40353) SpecialDoubleRedirect should support interwiki redirects.
* (bug 2865) User interface HTML elements don't use lang attribute
(completed the fix by adding the lang attribute to firstHeading)
* (bug 42173) Removed namespace prefixes on Special:UncategorizedCategories.
+* (bug 36053) Log in "returnto" feature forgets query parameters if no
+ title parameter was specified.
=== API changes in 1.21 ===
* prop=revisions can now report the contentmodel and contentformat, see docs/contenthandler.txt