<p><code data-x="attr-hyperlink-rel">rel</code>'s <span

data-x="concept-supported-tokens">supported tokens</span> are the keywords defined in <a

href="#linkTypes">HTML link types</a> which are allowed on <code>a</code> and <code>area</code>

elements, impact the processing model, and are supported by the user agent. The possible <span

data-x="concept-supported-tokens">supported tokens</span> are <code

data-x="rel-noreferrer">noreferrer</code>, <code data-x="rel-noopener">noopener</code>, and <code

data-x="rel-opener">opener</code>. <code data-x="attr-hyperlink-rel">rel</code>'s <span

data-x="concept-supported-tokens">supported tokens</span> must only include the tokens from this

list that the user agent implements the processing model for.</p>

<li>

<p>Let <var>noopener</var> be true if one of the following is true:</p>

<ul class="brief">

<li><var>subject</var>'s <a href="#linkTypes">link types</a> include the <code

data-x="rel-noreferrer">noreferrer</code> or <code data-x="rel-noopener">noopener</code>

keyword.</li>

<li id="opener-processing-model"><var>subject</var>'s <a href="#linkTypes">link types</a> do

not include the <code data-x="rel-opener">opener</code> keyword and

<var>targetAttributeValue</var> is an <span>ASCII case-insensitive</span> match for "<code

data-x="">_blank</code>".</li>

</ul>

</li>

<tr>

<td><code data-x="rel-opener">opener</code></td>

<td><em>not allowed</em></td>

<td><span data-x="hyperlink annotation">Annotation</span></td>

<td class="no"> &middot; </td>

<td>Creates an <span>auxiliary browsing context</span> if the hyperlink would otherwise create

a <span>top-level browsing context</span> that is not an <span>auxiliary browsing

context</span> (i.e., has "<code data-x="">_blank</code>" as <code

data-x="attr-hyperlink-target">target</code> attribute value).</td>

</tr>

<p w-nodev class="note">See also the <a href="#noopener">processing model</a> where the branching

between an <span>auxiliary browsing context</span> and a <span>top-level browsing context</span>

is defined.</p>

<h5>Link type "<dfn><code data-x="rel-opener">opener</code></dfn>"</h5>

<p>The <code data-x="rel-opener">opener</code> keyword may be used with <code>a</code> and

<code>area</code> elements. This keyword does not create a <span>hyperlink</span>, but <span

data-x="hyperlink annotation">annotates</span> any other hyperlinks created by the element (the

implied hyperlink, if no other keywords create one).</p>

<p>The keyword indicates that any newly created <span>top-level browsing context</span> which

results from following the <span>hyperlink</span> will be an <span>auxiliary browsing

context</span>.</p>

<p w-nodev class="note">See also the <a href="#opener-processing-model">processing model</a>.</p>

<div class="example">

<p>In the following example the <code data-x="rel-opener">opener</code> is used to allow the help

page popup to navigate its opener, e.g., in case what the user is looking for can be found

elsewhere. An alternative might be to use a named target, rather than <code

data-x="">_blank</code>, but this has the potential to clash with existing names.</p>

<pre><code class="html" data-x="">&lt;a href="..." <mark>rel=opener</mark> target=_blank>Help!&lt;/a></code></pre>

</div>