The a (or anchor) 1) is a html element that represents a hyperlink.
It is the cornerstone:
See HTML - Hyper(Link) (href elements) on how to get them
See Google Analytics - Outbound Link Tracking
example on how to get the href in XSL
<xsl:element name="a">
<xsl:attribute name="href">
<xsl:value-of select="actionUrl"/>
</xsl:attribute>
<xsl:value-of select="actionUrl"/>
</xsl:element>
Deep anchors are icon that are located closed to element that when clicked will give the URL with the fragment that permits to navigate directly to the section or element that have the same value as id
Technically, this is just a local anchor with only the fragment that contains an icon / image.
An adapted version of the Rfc document using the content css element..
<a class="anchor" name="section-14.39" href="#section-14.39">
<h3>14.39 - Server</h3>
</a>
h3 {
margin-left: 30px;
}
.anchor::before {
opacity: 0;
content: "#";
position: absolute;
left:25px;
}
.anchor:hover:before {
opacity: 1;
}
/* The :hover>.class can also be used See https://developers.google.com/analytics/devguides/collection/analyticsjs/field-reference */
Another example with an icon:
<a href="#deep_anchors">
<svg aria-hidden="true" width="18" height="18" viewBox="0 0 18 18"><path d="M7.22 11.83a6 6 0 001.62.85l.61-1.8a4.1 4.1 0 114.04-.8l1.26 1.42a6 6 0 10-7.53.33zm3.43-5.6a6 6 0 00-1.6-.87L8.4 7.15a4.1 4.1 0 11-4.05.73L3.12 6.43a6 6 0 107.53-.2z"></path></svg>
</a>
If you want to create direct navigation link, you can also use the dfn (defining term) element