base

There must be no more than one base element per document. A base element must have either an href attribute, a target attribute, or both.

<!DOCTYPE html>
<html>
 <head>
 <title>base element example</title>
 <base href="https://gethtml.at/">
 </head>
 <body>
 <p>A <a href="some-file.html">relative link</a>.</p>
 <!-- after resolving the above link equals to -->
 <p>A <a href="https://gethtml.at/some-file.html">relative link</a>.</p>
 </body>
</html>
base element example

A relative link.

A relative link.

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