XSLT 2.0 and XPath 2.0 Programmer's Reference, 4th Edition (79 page)
- If the
as
attribute is a QName, the QName must identify an atomic type. The
type
attribute is always a QName, and this may be any type defined in an imported schema: complex types are allowed as well as all three varieties of simple type; that is list types, union types, and atomic types.
- The
as
attribute can include an occurrence indicator (
?
,
*
, or
+
). The
type
attribute never includes an occurrence indicator.
- The
as
attribute may define node kinds, for example
node()
,
element()
, or
comment()
. Such constructs are never used in the
type
attribute.