The namespace command

Syntax:

Binds a namespace prefix to a URI. QNames using this prefix may be used in subsequent XPath expressions within the script.

Note that the conventional prefixes xml, xsl, saxon, xs, xsi, fn, math, map, and array are already bound to the conventional namespace URIs.

In path expressions, unprefixed names match by local name only, so it is usually possible to select elements without binding a namespace prefix.