> Uh, it indeed seems that uri-collection behaves differently to collection:
>


Indeed. The URI is invalid because the vertical bar should be escaped as %7C.
The collection() function is recovering from that by applying the iri-to-uri()
function; the uri-collection() function should probably do the same. And if
the URI is still invalid, the error message should make a better attempt to
explain why.

Michael Kay
Saxonica