Tag archeology

January 14 2011

Today I learned about the <base> tag:

Defines the base location for links on a page.

To get all the relative links at http://site1.com/my_page.html to point to http://site2.com/stuff/, the <base> tag is a way to do that:

<head>
  <base href='http://site2.com/stuff/'>
</head>
...
<body>
  ...
  <a href='page.html'>This link</a> points to http://site2.com/stuff/page.html
  and not http://site1.com/page.html.
  ...
</body>

This tag wasn’t part of the first informal HTML specification, but it’s in the HTML 2.0 specification. This means that between 1991 and 1995 somebody found a valid use-case for this tag and got it included ... It probably seemed like a good idea at the time. The <base> tag might be one of the least used tag on the web, it certainly is one of the least useful.