checking for syntax of datatypeLibrary and ns attributes

The specification says:

: In addition to the attributes shown explicitly, any element can have an ns
: attribute and any element can have a datatypeLibrary attribute. The ns
: attribute can have any value. The value of the datatypeLibrary attribute must
: match the anyURI symbol as described in the previous paragraph; in addition, it
: must not use the relative form of URI reference and must not have a fragment
: identifier; as an exception to this, the value may be the empty string.

Are both 'ns' and 'datatypeLibrary' restricted to be absolute URIs with no fragment
identifier, or just datatypeLibrary?

David