This
section
is
non-normative.
This
section
introduces
the
RDF
/XML
syntax,
describes
how
it
encodes
RDF
graphs
and
explains
this
with
examples.
If
there
is
any
conflict
between
this
informal
description
and
the
formal
description
of
the
syntax
and
grammar
in
sections
5.
Syntax
Data
Model
and
6.
RDF
/XML
Grammar
,
the
latter
two
sections
take
precedence.
This
document
specifies
the
syntax
of
RDF
/XML
as
a
grammar
on
an
alphabet
of
symbols.
The
symbols
are
called
events
in
the
style
of
the
XPATH
Information
Set
Mapping
.
A
sequence
of
events
is
normally
derived
from
an
XML
document,
in
which
case
they
are
in
document
order
as
defined
below
in
5.2
Information
Set
Mapping
.
The
sequence
these
events
form
are
intended
to
be
similar
to
the
sequence
of
events
produced
by
the
[
SAX
]
XML
API
from
the
same
XML
document.
Sequences
of
events
may
be
checked
against
the
grammar
to
determine
whether
they
are
or
are
not
syntactically
well-formed
RDF
/XML.
The
RDF
1.2
Concepts
and
Abstract
Syntax
specification
[
RDF12-CONCEPTS
]
defines
four
types
of
RDF
terms
:
IRIs
,
literals
,
blank
nodes
,
and
triple
terms
.
Literals
are
composed
of
a
lexical
form
and
an
optional
language
tag
[
BCP47
]
–
possibly
including
a
base
direction
–
or
datatype
IRI
.
An
extra
type,
prefix
,
is
used
during
parsing
to
map
string
identifiers
to
namespace
IRIs.
The
grammar
productions
may
include
actions
which
fire
when
the
production
is
recognized.
Taken
together
these
actions
define
a
transformation
from
any
syntactically
well-formed
RDF
/XML
sequence
of
events
into
a
set
of
triples
by
mapping
matching
productions
to
RDF
terms
or
their
components
(e.g.,
language
tags,
lexical
forms
of
literals).
Grammar
productions
change
the
parser
state
and
emit
triples.
The
model
given
here
illustrates
one
way
to
create
a
representation
of
an
RDF
Graph
from
an
RDF
/XML
document.
It
does
not
mandate
any
implementation
method
—
any
other
method
that
results
in
a
representation
of
the
same
RDF
Graph
may
be
used.
In
particular:
-
This
specification
permits
any
representation
of
an
RDF
graph;
graph
;
in
particular,
it
does
not
require
the
use
of
N-Triples
[
RDF12-N-TRIPLES
].
-
This
specification
does
not
require
the
use
of
[
XPATH
]
or
[
SAX
]
-
This
specification
places
no
constraints
on
the
order
in
which
software
transforming
RDF
/XML
into
a
representation
of
a
graph,
constructs
the
representation
of
the
graph.
-
Software
transforming
RDF
/XML
into
a
representation
of
a
graph
MAY
eliminate
duplicate
predicate
arcs.
The
syntax
does
not
support
non-well-formed
XML
documents,
nor
documents
that
otherwise
do
not
have
an
XML
Information
Set
[
XML-INFOSET
];
for
example,
that
do
not
conform
to
Namespaces
in
XML
[
XML-NAMES
].
The
Infoset
requires
support
for
XML
Base
[
XMLBASE
].
RDF
/XML
uses
the
information
item
property
[base
IRI],
discussed
in
4.3
Resolving
IRIs
This
specification
requires
an
XML
Information
Set
[
XML-INFOSET
]
which
supports
at
least
the
following
information
items
and
properties
for
RDF
/XML:
-
document
information
item
-
[document
element],
[children],
[base
IRI]
-
element
information
item
-
[local
name],
[namespace
name],
[children],
[attributes],
[parent],
[base
IRI]
-
attribute
information
item
-
[local
name],
[namespace
name],
[normalized
value]
-
character
information
item
-
[character
code]
There
is
no
mapping
of
the
following
items
to
data
model
events:
Other
information
items
and
properties
have
no
mapping
to
syntax
data
model
events.
Element
information
items
with
reserved
XML
Names
(See
Name
in
Extensible
Markup
Language
(XML)
1.1
(Second
Edition)
)
are
not
mapped
to
data
model
element
events.
These
are
all
those
with
property
[prefix]
beginning
with
xml
(case
independent
comparison)
and
all
those
with
[prefix]
property
having
no
value
and
which
have
[local
name]
beginning
with
xml
(case
independent
comparison).
All
information
items
contained
inside
XML
elements
matching
the
parseTypeLiteralPropertyElt
production
form
XML
literals
and
do
not
follow
this
mapping.
See
parseTypeLiteralPropertyElt
for
further
information.
This
section
is
intended
to
satisfy
the
requirements
for
Conformance
in
the
[
XML-INFOSET
]
specification.
It
specifies
the
information
items
and
properties
that
are
needed
to
implement
this
specification.
There
are
nine
types
of
event
defined
in
the
following
subsections.
Most
events
are
constructed
from
an
Infoset
information
item
(except
for
IRI
,
blank
node
,
literal
with
no
explicit
datatype
and
typed
literal
).
The
effect
of
an
event
constructor
is
to
create
a
new
event
with
a
unique
identity,
distinct
from
all
other
events.
Events
have
accessor
operations
on
them
and
most
have
the
string-value
,
IRI
,
rdf-term
,
literal
,
or
bnode
accessors
that
may
be
a
static
value
or
computed.
Constructed
from
a
document
information
item
and
takes
the
following
accessors
and
values.
-
document-element
-
Set
to
the
value
of
document
information
item
property
[document-element].
-
children
-
Set
to
the
value
of
document
information
item
property
[children].
-
base-iri
-
Set
to
the
value
of
document
information
item
property
[base
IRI].
-
language
-
Set
to
the
empty
string.
-
direction
-
Set
to
the
empty
string.
-
graph
-
The
graph
used
for
collecting
emitted
triples,
initialized
to
a
new
RDF
graph
.
Constructed
from
an
element
information
item
and
takes
the
following
accessors
and
values:
-
local-name
-
Set
to
the
value
of
element
information
item
property
[local
name].
-
namespace-name
-
Set
to
the
value
of
element
information
item
property
[namespace
name].
-
children
-
Set
to
the
value
of
element
information
item
property
[children].
-
parent
-
Set
to
the
value
of
element
information
item
property
[parent].
-
base-iri
-
Set
to
the
value
of
element
information
item
property
[base
IRI].
-
attributes
-
Made
from
the
value
of
element
information
item
property
[attributes]
which
is
a
set
of
attribute
information
items.
If
this
set
contains
an
attribute
information
item
xml:lang
([namespace
name]
property
with
the
value
"http://www.w3.org/XML/1998/namespace"
and
[local
name]
property
value
"lang")
it
is
removed
from
the
set
of
attribute
information
items
and
the
·
language
·
accessor
is
set
to
the
[normalized-value]
property
of
the
attribute
information
item.
If
the
element
has
a
version
accessor
with
the
value
"1.2"
or
greater,
this
set
contains
an
attribute
information
item
its:dir
([namespace
name]
property
with
the
value
"http://www.w3.org/2005/11/its"
and
[local
name]
property
value
"dir")
it
is
removed
from
the
set
of
attribute
information
items
and
the
·
direction
·
accessor
is
set
to
the
[normalized-value]
property
of
the
attribute
information
item,
which
MUST
be
one
of
"ltr"
,
"rtl"
,
or
the
empty
string.
If
the
element
has
a
version
accessor
with
the
value
"1.2"
or
greater,
this
set
contains
an
attribute
information
item
its:version
([namespace
name]
property
with
the
value
"http://www.w3.org/2005/11/its"
and
[local
name]
property
value
"version")
it
is
removed
from
the
set
of
attribute
information
items
and
the
·
its-version
·
accessor
is
set
to
the
[normalized-value]
property
of
the
attribute
information
item.
All
remaining
reserved
XML
Names
(see
Name
in
Extensible
Markup
Language
(XML)
1.1
(Second
Edition)
)
are
now
removed
from
the
set.
These
are,
all
attribute
information
items
in
the
set
with
property
[prefix]
beginning
with
xml
(case
independent
comparison)
and
all
attribute
information
items
with
[prefix]
property
having
no
value
and
which
have
[local
name]
beginning
with
xml
(case
independent
comparison)
are
removed.
Note
that
the
[base
IRI]
accessor
is
computed
by
XML
Base
before
any
xml:base
attribute
information
item
is
deleted.
The
remaining
set
of
attribute
information
items
are
then
used
to
construct
a
new
set
of
Attribute
Events
which
is
assigned
as
the
value
of
this
accessor.
-
IRI
-
Set
to
an
IRI
constructed
from
the
concatenation
of
the
value
of
the
namespace-name
accessor
and
the
value
of
the
local-name
accessor.
-
-
li-counter
-
Set
to
the
integer
value
1.
-
language
-
Set
from
the
·
attributes
·
as
described
above.
If
no
value
is
given
from
the
attributes,
the
value
is
set
to
the
value
of
the
language
accessor
on
the
parent
event
(either
a
Root
Event
or
an
Element
Event
),
which
may
be
the
empty
string.
-
direction
-
Set
from
the
·
attributes
·
as
described
above.
If
no
value
is
given
from
the
attributes,
the
value
is
set
to
the
value
of
the
direction
accessor
on
the
parent
event
(either
a
Root
Event
or
an
Element
Event
),
which
may
be
the
empty
string.
-
version
-
Set
from
the
·
attributes
·
as
described
above.
If
no
value
is
given
from
the
attributes,
the
value
is
set
to
the
value
of
the
version
accessor
on
the
parent
event
(either
a
Root
Event
or
an
Element
Event
).
-
its-version
-
Set
from
the
·
attributes
·
as
described
above.
If
no
value
is
given
from
the
attributes,
the
value
is
set
to
the
value
of
the
version
accessor
on
the
parent
event
(either
a
Root
Event
or
an
Element
Event
),
which
SHOULD
be
set
to
"2.0"
.
-
subject
-
Has
no
initial
value.
Takes
a
value
that
is
an
Identifier
event.
event,
or
a
triple
term
.
This
accessor
is
used
on
elements
that
deal
with
one
node
in
the
RDF
graph,
graph
,
this
generally
being
the
subject
of
an
RDF
triple
.
-
graph
-
The
graph
used
for
collecting
emitted
triples.
The
initial
value
is
taken
from
the
parent
event
(either
a
Root
Event
or
an
Element
Event
),
or
a
new
RDF
graph
,
if
not
set.
May
be
modified
by
a
parseType="Triple"
attribute.
Has
no
accessors.
Marks
the
end
of
the
containing
element
in
the
sequence.
Constructed
from
an
attribute
information
item
and
takes
the
following
accessors
and
values:
-
local-name
-
Set
to
the
value
of
attribute
information
item
property
[local
name].
-
namespace-name
-
Set
to
the
value
of
attribute
information
item
property
[namespace
name].
-
string-value
-
Set
to
the
value
of
the
attribute
information
item
property
[normalized
value]
as
specified
by
[
XML11
]
(if
an
attribute
whose
normalized
value
is
a
zero-length
string,
then
the
string-value
is
also
a
zero-length
string).
-
IRI
-
If
·
namespace-name
·
is
present,
set
to
an
IRI
constructed
from
the
concatenation
of
the
value
of
the
·
namespace-name
·
accessor
and
the
value
of
the
·
local-name
·
accessor.
Otherwise
if
·
local-name
·
is
ID
,
about
,
parseType
,
resource
,
type
,
or
version
,
set
to
an
IRI
constructed
from
the
value
of
the
concatenation
of
the
RDF
namespace
IRI
and
the
value
of
the
local-name
accessor.
Other
non-namespaced
·
local-name
·
accessor
values
are
forbidden.
The
support
for
a
limited
set
of
non-namespaced
names
is
REQUIRED
and
intended
to
allow
RDF
/XML
documents
specified
in
[
RDF-SYNTAX-GRAMMAR-19990222
]
to
remain
valid;
new
documents
SHOULD
NOT
use
these
unqualified
attributes
and
applications
MAY
choose
to
warn
when
the
unqualified
form
is
seen
in
a
document.
The
construction
of
IRIs
from
XML
attributes
can
generate
the
same
IRIs
from
different
XML
attributes.
This
can
cause
ambiguity
in
the
grammar
when
matching
attribute
events
(such
as
when
rdf:about
and
about
XML
attributes
are
both
present).
Documents
that
have
this
are
illegal.
-
rdf-term
-
The
value
is
an
IRI
constructed
from
string-value
resolved
against
the
·
base-iri
·
accessor
of
the
containing
element.
-
Constructed
from
a
sequence
of
one
or
more
consecutive
character
information
items
.
Has
the
single
accessor:
-
string-value
-
Set
to
the
value
of
the
string
made
from
concatenating
the
[
character
code
]
property
of
each
of
the
character
information
items.
An
event
for
a
IRIs
an
IRI
which
has
the
following
accessors:
-
identifier
-
Takes
a
string
value
used
as
an
IRI
.
-
rdf-term
-
-
The
value
is
an
IRI
constructed
from
the
value
of
the
·
identifier
·
accessor.
These
events
are
constructed
by
giving
a
value
for
the
·
identifier
·
accessor.
For
further
information
on
identifiers
in
RDF
,
see
4.2
Identifiers
.
An
event
for
an
triple
term
which
has
the
following
accessors:
-
rdf-term
-
The
value
is
a
triple
term
.
These
events
are
constructed
by
giving
a
value
to
the
rdf-term
accessor.
An
event
for
a
typed
literal
which
can
have
the
following
accessors:
-
literal-value
-
Takes
a
string
value.
-
literal-datatype
-
Takes
a
string
value
used
as
an
IRI
.
-
literal
-
-
The
value
is
an
RDF
literal
with
the
lexical
form
taken
from
the
value
of
the
·
literal-value
·
accessor
and
datatype
IRI
taken
from
the
value
of
the
·
literal-datatype
·
accessor.
These
events
are
constructed
by
giving
values
for
the
·
literal-value
·
and
·
literal-datatype
·
accessors.
Note
Interoperability
Note
(Informative):
Literals
beginning
with
a
Unicode
combining
character
are
allowed
however
they
may
cause
interoperability
problems.
See
[
CHARMOD
]
for
further
information.
Note
Implementation
Note
(Informative):
In
XML
Schema
(part
1)
[
XMLSCHEMA11-2
],
white
space
normalization
occurs
during
validation
according
to
the
value
of
the
whiteSpace
facet.
The
syntax
mapping
used
in
this
document
occurs
after
this,
so
the
whiteSpace
facet
formally
has
no
further
effect.
To
transform
the
Infoset
into
the
sequence
of
events
in
document
order
,
each
information
item
is
transformed
as
described
above
to
generate
a
tree
of
events
with
accessors
and
values.
Each
element
event
is
then
replaced
as
described
below
to
turn
the
tree
of
events
into
a
sequence
in
document
order.
-
The
original
element
event
-
The
value
of
the
children
accessor
recursively
transformed,
a
possibly
empty
ordered
list
of
events.
-
An
end
element
event
The
following
notation
is
used
to
describe
matching
the
sequence
of
data
model
events
as
given
in
5.
Syntax
Data
Model
and
the
actions
to
perform
for
the
matches.
The
RDF
/XML
grammar
is
defined
in
terms
of
mapping
from
these
matched
data
model
events
to
triples,
using
notation
of
the
form:
number
event-type
event-content
where
the
event-content
is
an
expression
matching
event-types
(as
defined
in
5.1
Events
),
using
notation
given
in
the
following
sections.
The
number
is
used
for
reference
purposes.
The
grammar
action
may
include
generating
new
triples
to
the
graph,
written
in
N-Triples
[
RDF12-N-TRIPLES
]
format.
graph.
The
following
sections
describe
the
general
notation
used
and
that
for
event
matching
and
actions.
|
Notation
|
Meaning
|
|
A
==
B
|
Event
accessor
A
matches
expression
B.
|
|
A
!=
B
|
A
is
not
equal
to
B.
|
|
A
|
B
|
...
|
The
A,
B,
...
terms
are
alternatives.
|
|
A
-
B
|
The
terms
in
A
excluding
all
the
terms
in
B.
|
|
anyURI
.
|
Any
URI.
|
|
anyString
.
|
Any
string.
|
|
list(item1,
item2,
...);
list()
|
An
ordered
list
of
events.
An
empty
list.
|
|
set(item1,
item2,
...);
set()
|
An
unordered
set
of
events.
An
empty
set.
|
|
*
|
Zero
or
more
of
preceding
term.
|
|
?
|
Zero
or
one
of
preceding
term.
|
|
+
|
One
or
more
of
preceding
term.
|
root(acc1
==
value1,
acc2
==
value2,
...)
|
Match
a
Root
Event
with
accessors.
|
start-element(acc1
==
value1,
acc2
==
value2,
...)
children
end-element()
|
Match
a
sequence
of
Element
Event
with
accessors,
a
possibly
empty
list
of
events
as
element
content
and
an
End
Element
Event
.
|
attribute(acc1
==
value1,
acc2
==
value2,
...)
|
Match
an
Attribute
Event
with
accessors.
|
|
text()
|
Match
a
Text
Event
.
|
|
Notation
|
Meaning
|
|
A
:=
B
|
Assigns
A
the
value
B.
|
|
concat(A,
B,
..)
|
A
string
created
by
concatenating
the
terms
in
order.
|
|
resolve(
e
,
s
)
|
An
IRI
created
by
interpreting
s
as
a
relative
IRI
reference
to
the
·
base-iri
·
accessor
of
e
as
defined
in
4.3
Resolving
IRIs
.
|
|
generated-blank-node-id()
|
A
string
value
for
a
new
distinct
generated
blank
node
identifier
as
defined
in
4.2
Identifiers
.
|
|
event
.
accessor
:=
value
|
Sets
an
event
accessor
to
the
given
value.
|
|
iri(identifier
:=
value)
|
Create
a
new
IRI
Event
.
|
|
bnodeid(identifier
:=
value)
|
Create
a
new
Blank
Node
Identifier
Event
.
See
also
section
4.2
Identifiers
.
|
literal(literal-value
:=
string,
literal-language
:=
language,
literal-direction
:=
direction,
...)
|
Create
a
new
Literal
Without
Datatype
Event
.
|
|
string(iri)
|
The
string
value
of
an
IRI
.
|
|
typed-literal(literal-value
:=
string,
...)
|
Create
a
new
Typed
Literal
Event
.
|
|
triple(s,
p,
o)
|
Create
a
new
Triple
Term
Event
composed
of
s
,
p
,
and
o
. |
This
section
is
non-normative.
This
section
is
non-normative.
This
document
is
a
product
of
extended
deliberations
by
the
RDF
Core
working
group,
whose
members
have
included:
Art
Barstow
(
W3C
)
Dave
Beckett
(ILRT),
Dan
Brickley
(
W3C
/ILRT),
Dan
Connolly
(
W3C
),
Jeremy
Carroll
(Hewlett
Packard),
Ron
Daniel
(Interwoven
Inc),
Bill
dehOra
(InterX),
Jos
De
Roo
(AGFA),
Jan
Grant
(ILRT),
Graham
Klyne
(Clearswift
and
Nine
by
Nine),
Frank
Manola
(MITRE
Corporation),
Brian
McBride
(Hewlett
Packard),
Eric
Miller
(
W3C
),
Stephen
Petschulat
(IBM),
Patrick
Stickler
(Nokia),
Aaron
Swartz
(HWG),
Mike
Dean
(BBN
Technologies
/
Verizon),
R.
V.
Guha
(Alpiri
Inc),
Pat
Hayes
(IHMC),
Sergey
Melnik
(Stanford
University),
Martyn
Horner
(Profium
Ltd).
This
specification
also
draws
upon
an
earlier
RDF
Model
and
Syntax
document
edited
by
Ora
Lassilla
and
Ralph
Swick,
and
RDF
Schema
edited
by
Dan
Brickley
and
R.
V.
Guha.
RDF
and
RDF
Schema
Working
group
members
who
contributed
to
this
earlier
work
are:
Nick
Arnett
(Verity),
Tim
Berners-Lee
(
W3C
),
Tim
Bray
(Textuality),
Dan
Brickley
(ILRT
/
University
of
Bristol),
Walter
Chang
(Adobe),
Sailesh
Chutani
(Oracle),
Dan
Connolly
(
W3C
),
Ron
Daniel
(DATAFUSION),
Charles
Frankston
(Microsoft),
Patrick
Gannon
(CommerceNet),
RV
Guha
(Epinions,
previously
of
Netscape
Communications),
Tom
Hill
(Apple
Computer),
Arthur
van
Hoff
(Marimba),
Renato
Iannella
(DSTC),
Sandeep
Jain
(Oracle),
Kevin
Jones,
(InterMind),
Emiko
Kezuka
(Digital
Vision
Laboratories),
Joe
Lapp
(webMethods
Inc.),
Ora
Lassila
(Nokia
Research
Center),
Andrew
Layman
(Microsoft),
Ralph
LeVan
(OCLC),
John
McCarthy
(Lawrence
Berkeley
National
Laboratory),
Chris
McConnell
(Microsoft),
Murray
Maloney
(Grif),
Michael
Mealling
(Network
Solutions),
Norbert
Mikula
(DataChannel),
Eric
Miller
(OCLC),
Jim
Miller
(
W3C
,
emeritus),
Frank
Olken
(Lawrence
Berkeley
National
Laboratory),
Jean
Paoli
(Microsoft),
Sri
Raghavan
(Digital/Compaq),
Lisa
Rein
(webMethods
Inc.),
Paul
Resnick
(University
of
Michigan),
Bill
Roberts
(KnowledgeCite),
Tsuyoshi
Sakata
(Digital
Vision
Laboratories),
Bob
Schloss
(IBM),
Leon
Shklar
(Pencom
Web
Works),
David
Singer
(IBM),
Wei
(William)
Song
(SISU),
Neel
Sundaresan
(IBM),
Ralph
Swick
(
W3C
),
Naohiko
Uramoto
(IBM),
Charles
Wicksteed
(Reuters
Ltd.),
Misha
Wolf
(Reuters
Ltd.),
Lauren
Wood
(SoftQuad).
This
section
is
non-normative.
In
addition
to
the
editors,
the
following
people
have
contributed
to
this
specification:
Denis
Ah-Kang,
Dominik
Tomaszuk,
Peter
F.
Patel-Schneider,
Pierre-Antoine
Champin,
and
Ted
Thibodeau
Jr
Members
of
the
RDF
-star
Working
Group
Group
included
Vladimir
Alexiev,
Amin
Anjomshoaa,
Julián
Arenas-Guerrero,
Dörthe
Arndt,
Bilal
Ben
Mahria,
Erich
Bremer,
Kurt
Cagle,
Rémi
Ceres,
Pierre-Antoine
Champin,
Souripriya
Das,
Daniil
Dobriy,
Enrico
Franconi,
Jeffrey
Phillips
Freeman,
Fabien
Gandon,
Benjamin
Goering,
Adrian
Gschwend,
Olaf
Hartig,
Timothée
Haudebourg,
Ian
Horrocks,
Gregg
Kellogg,
Mark
Kim,
Jose
Emilio
Labra
Gayo,
Ora
Lassila,
Richard
Lea,
Niklas
Lindström,
Pasquale
Lisena,
Thomas
Lörtsch,
Matthew
Nguyen,
Peter
Patel-Schneider,
Thomas
Pellissier
Tanon,
Dave
Raggett,
Jean-Yves
ROSSI,
Felix
Sasaki,
Andy
Seaborne,
Ruben
Taelman,
Ted
Thibodeau
Jr,
Dominik
Tomaszuk,
Raphaël
Troncy,
William
Van
Woensel,
Gregory
Williams,
Jesse
Wright,
Achille
Zappa,
and
Antoine
Zimmermann.
Editor's
note
Recognize
members
of
the
Task
Force?
Not
an
easy
to
find
list
of
contributors.
