+ Specifies a permanent link to the page, if different than the page
+ generated by ikiwiki.
+
+* date
+
+ Specifies the creation date of the page. The date can be entered in
+ nearly any format, since it's parsed by [[cpan TimeDate]].
+
+* stylesheet
+
+ Adds a stylesheet to a page. The stylesheet is treated as a wiki link to
+ a `.css` file in the wiki, so it cannot be used to add links to external
+ stylesheets. Example:
+
+ \[[meta stylesheet=somestyle rel="alternate stylesheet"
+ title="somestyle"]]
+
+* openid
+
+ Adds html <link> tags to perform OpenID delegation to an external
+ OpenID server. This lets you use an ikiwiki page as your OpenID. Example:
+
+ \\[[meta openid="http://joeyh.myopenid.com/"
+ server="http://www.myopenid.com/server"]]
+
+If the field is not one of the above predefined fields, the metadata will be
+written to the generated html page as a <meta> header. However, this
+won't be allowed if the [[htmlscrubber]] is enabled, since it can be used to
+insert unsafe content.