Not all documents have a base URI.

What happens when you POST an XML document? There is no URI for the client...

What happens in a pipeline when you chain two XSLT stylesheets together?

• The result of the first transform doesn't have a base URI.

• Relative links won't work until it is serialized.

This means that documents can be broken after you author them.

Example:

This link to 'bio.xml' has no resolveable URI under HTTP POST:

<person bio="bio.xml">
<name>Alex Milowski</name>
</person>