HTML <base> element
<base>
tag defines the default base URL of all links in the web page. It's a void
tag, and no closing tag such as </base> is needed.
<base>
tag is usually placed between <head> ... <head> section.
If the following base tag is placed between <head> ... <head> section, then the followed links will be the same:
<base href="http://https://convert.idontcarewhatyouthink.net/">
<a href="index.php">Default link</a> <a href="http://https://convert.idontcarewhatyouthink.net/index.php">Default link</a> <a href="/index.php">Default link</a>
Default link
Default link
Default link