<p>All <a for=/>documents</a> have an associated <dfn>list of pending fullscreen events</dfn>, which

is an <a>ordered set</a> of (<a>string</a>, <a>element</a>) <a>tuples</a>. It is initially empty.

<p>To <dfn>fullscreen an <var>element</var></dfn>, set <var>element</var>'s <a>fullscreen flag</a>

and <a for="top layer">add</a> it to its <a>node document</a>'s <a>top layer</a>.

<p>To <dfn>fullscreen an <var>element</var></dfn>:

<ol>

<li><p>Run <a>hide all popovers</a> given <var>element</var>'s <a>node document</a>.

<li><p>Set <var>element</var>'s <a>fullscreen flag</a>.

<li><p><a for="top layer">Add</a> <var>element</var> to <var>element</var>'s <a>node document</a>'s

<a>top layer</a>.

</ol>

<p>To <dfn>unfullscreen an <var>element</var></dfn>, unset <var>element</var>'s

<a>fullscreen flag</a> and <a>iframe fullscreen flag</a> (if any), and <a for=set>remove</a> it from

<li><p><var>element</var>'s <a>node document</a> is <a>allowed to use</a> the "<code><a

data-lt="fullscreen-feature">fullscreen</a></code>" feature.

<!-- cross-process, recursive -->

<li><p><var>element</var> <a for=Element>namespace</a> is not the <a>HTML namespace</a> or

<var>element</var>'s <a>popover visibility state</a> is <a for="popover visibility

state">hidden</a>.

</ul>

<div algorithm="requestFullscreen(options)">