XSLT 2.0 and XPath 2.0 Programmer's Reference, 4th Edition (809 page)

Element (XML)

A logical unit within an XML document, delimited by start and end
tags
, for example
Wrox

; an empty element may also be written in abbreviated form, for example
name=“Wrox”/>
.

Element Declaration (Schema)

An element declaration is a
schema component
that corresponds to an

element
in a
schema
: it defines the structure of
elements
having a particular name. It may be a global element declaration (if it is defined at the top level of a schema) or a local element declaration (if defined within the structure of a
complex type
).

Element Node (XDM)

A
node
in a
tree
that represents an
element
in an XML
document
. The
parent
of the element node is either the containing element or the
document node
of the tree; its
children
are the element nodes,
text nodes
,
comment nodes
, and
processing instruction nodes
derived from the immediate content of the XML element.

Embedded Stylesheet Module (XSLT)

A
stylesheet module
that does not constitute an entire XML
document
in its own right, but is embedded as an

element within some larger XML (or perhaps non-XML) document.

Empty Sequence (XDM)

An empty sequence is a
sequence
containing no
items
. It can be written as
()
in XPath
.

Entity Reference (XML)

A reference to an internal or external
entity
, generally in the form
&name;
. Note that numeric references of the form

are correctly referred to as
character references
rather than entity references.

Entity (XML)

A physical unit of information that may be referenced within an XML
document
. Internal entities are embedded within the document in its
Document Type Definition
; external entities are generally held as a separate file. A parsed entity contains text with XML markup; an
unparsed entity
contains binary data. A general entity contains material for inclusion in the document; a parameter entity contains material for inclusion in the Document Type Definition.

Expanded QName (XDM)

The term QName is sometimes used to mean a QName as written in source XML documents, that is a construct of the form
prefix:local-name
, and it is sometimes used to mean the (
namespace-uri
,
local-name
) pair that this represents. Within the XSLT 2.0 and XPath 2.0 specifications the preferred usage is
lexical QName
for the first construct, and
expanded QName
for the second. These terms are not consistent across the full range of XML specifications.There is no standard convention for displaying an expanded QName, though in some interfaces such as JAXP, expanded QNames are written in the form
{namespace-uri}local-name
. This is sometimes referred to as Clark notation.

Expression (XPath)

An XPath construct that can be evaluated to yield a value, which will always be a
sequence
(of
nodes
and/or
atomic values
). In XSLT, expressions are used in many contexts such as the
select
attribute of

,

, and

, and the
test
attribute of

and

. Expressions are also used between curly braces in
attribute value templates
.

Extension Attribute (XSLT)

An
attribute
in a vendor- or user-defined
namespace
used on an XSLT
element
in the
stylesheet
. Such attributes may be used to control behavior that would otherwise be implementation defined, or to provide extra control over
serialization
.

Extension Function (XSLT)