QNames in attribute values considered useful
Quite some time ago (around XML raise as a universal data format), the W3C seemed to be in doubt of the value of QNames (prefix + local name) in attribute values.
One very clean evidence of this inconsistency around the best practice on QNames on attribute values is the W3C XML Schema specification, which was pretty happy with QNames in attributes:
<?xml version="1.0" encoding="utf-8"?>
<xs:schema targetNamespace="my-schema" ...
