Page authors use the mcs:frame-page meta property to specify that the associated html element contains a frame page.
Page authors use the mcs:frame-page meta property to specify that the associated html element contains a frame page.
This meta property is associated with the containing page fragment, i.e. the closest enclosing html element. It can appear anywhere within that page fragment but must have no about attribute. It is a non-fatal error if the meta property is specified multiple times on the same html element, in that case the first one wins, the rest are ignored. The content attribute is ignored.
In addition to marking a page fragment as a frame page, page authors can use this meta property to associate arbitrary data with the page using JSON markup. For example:
<meta property="mcs:frame-page">
<json:object>
<json:property name="special">
<json:boolean>true</json:boolean>
</json:property>
</json:object>
</meta>