2.2 Namespaces
After listing the prefixes fn:, xs: and xdt:, it says
"All these prefixes are assumed to be bound to the appropriate URIs."
Please list the appropriate URIs, instead of
burdening the reader with crossreferencing to other documents.
Or if you wish to avoid the problem of listing the same information
in mulitple documents, you could at least provide a cross-reference,
preferably with a hot link.