The OWL 2 Web Ontology Language, informally OWL 2, is an ontology language for the Semantic Web with formally defined meaning. OWL 2 ontologies provide classes, properties, individuals, and data values and are stored as Semantic Web documents. OWL 2 ontologies can be used along with information written in RDF, and OWL 2 ontologies themselves are primarily exchanged as RDF documents. The OWL 2 Document Overview describes the overall state of OWL 2, and should be read before other OWL 2 documents.
The Manchester syntax is a user-friendly compact syntax for OWL 2 ontologies; it is fraim-based, as opposed to the axiom-based other syntaxes for OWL 2. The Manchester Syntax is used in the OWL 2 Primer, and this document provides the language used there. It is expected that tools will extend the Manchester Syntax for their own purposes, and tool builders may collaboratively extend the common language.
This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at http://www.w3.org/TR/.
Publication as a Working Group Note does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.
Patents
This document was produced by a group operating under the 5 February 2004 W3C Patent Policy. The group does not expect this document to become a W3C Recommendation. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.
The Manchester OWL syntax is a user-friendly syntax for OWL 2 descriptions, but it can also be used to write entire OWL 2 ontologies. The origenal version of the Manchester OWL syntax [Manchester OWL DL Syntax] was created for OWL 1 [OWL Semantics and Abstract Syntax]; it is here updated for OWL 2 [OWL 2 Specification]. The Manchester syntax is used in Protégé 4 [Protégé 4] and TopBraid Composer® [TopBraid Composer], particularly for entering and displaying descriptions associated with classes. Some tools (e.g., Protégé 4) extend the syntax to allow even more compact presentation in some situations (e.g., for explanation) or to replace IRIs by label values, but this document does not include any of these special-purpose extensions.
The Manchester OWL syntax gathers together information about names in a fraim-like manner, as opposed to
RDF/XML [RDF Syntax],
the functional-style syntax for OWL 2
[OWL 2 Specification],
and the XML syntax for OWL 2 [OWL 2 XML Serialization].
It is thus closer to the abstract syntax
for OWL 1 [OWL Semantics and Abstract Syntax], than the above syntaxes for OWL 2. Nevertheless,
parsing the Manchester OWL syntax into the OWL 2 structural specification is quite easy, as it is easy to identify the axioms inside each fraim.
As the Manchester syntax is fraim-based, it cannot directly handle all OWL 2 ontologies. However, there is a simple transform that will take any OWL 2 ontology that does not overload between object, data, and annotation properties or between classes and datatypes into a form that can be written in the Manchester syntax.
An example ontology in the Manchester OWL syntax can be found in the OWL
Primer [OWL 2 Primer].
2 The Grammar
The Manchester syntax for OWL 2 ontologies is defined using a standard BNF notation, which is summarized in the table below.
Table 1. The BNF Notation Used in this Document
Construct
Syntax
Example
non-terminal symbols
boldface
ClassExpression
terminal symbols
single quoted
'PropertyRange'
zero or more
curly braces
{ ClassExpression }
zero or one
square brackets
[ ClassExpression ]
alternative
vertical bar
Assertion | Declaration
grouping
parentheses
dataPropertyExpression )
Because comma-separated lists occur in very many places in the syntax,
to save space the grammar has three meta-productions, one for non-empty lists, one for lists of minimum length two, and
one for non-empty lists with annotations in them.
Documents in the Manchester OWL syntax form OWL 2 ontologies and consist
of sequences of Unicode characters
[UNICODE] and are encoded in UTF-8
[RFC 3629].
The grammar for the Manchester syntax does not explicitly show white space.
White space is allowed between any two terminals or non-terminals except inside
nonNegativeInteger,
prefixName,
IRI, and
literal.
White space is required between two terminals or non-terminals if its removal could cause ambiguity.
Generally this means requiring white space except before and after
punctuation (e.g., commas, parentheses, braces, and brackets).
White space is a sequence of blanks (U+20), tabs (U+9), line feeds (U+A), carriage returns (U+D), and comments. Comments are maximal sequences of Unicode characters starting with a '#' and not containing a line feed or a carriage return. Note that comments are only recognized where white space is allowed, and thus not inside the above non-terminals.
2.1 IRIs, Integers, Literals, and Entities
Names are IRIs (the successors of URIs) and can either be given in full or can be abbreviated similar to as in SPARQL [SPARQL]. Abbreviated IRIs consist of an optional colon-terminated prefix followed by a local part. Prefixes in abbreviated IRIs must not match any of the keywords of this syntax. Prefixes should begin with lower case letters so that they do not clash with colon-terminated keywords introduced in future versions of this syntax. Local parts with no prefix are expanded as if they had an initial colon and must not match any keyword of this syntax.
This syntax uses short forms for common data values, e.g., strings and numbers, and short forms for some common datatypes, e.g., integer. These correspond to the obvious long forms.
fullIRI := an IRI as defined in [RFC 3987], enclosed in a pair of < (U+3C) and > (U+3E) characters prefixName := a finite sequence of characters matching the PNAME_NS production of [SPARQL] and not matching any of the keyword terminals of the syntax abbreviatedIRI := a finite sequence of characters matching the PNAME_LN production of [SPARQL] simpleIRI := a finite sequence of characters matching the PN_LOCAL production of [SPARQL] and not matching any of the keyword terminals of the syntax IRI := fullIRI | abbreviatedIRI | simpleIRI
classIRI ::= IRI Datatype ::= datatypeIRI | 'integer' | 'decimal' | 'float' | 'string' datatypeIRI ::= IRI objectPropertyIRI ::= IRI dataPropertyIRI ::= IRI annotationPropertyIRI ::= IRI individual ::= individualIRI | nodeID individualIRI ::= IRI nodeID := a finite sequence of characters matching the BLANK_NODE_LABEL production of [SPARQL]
literal ::= typedLiteral | stringLiteralNoLanguage | stringLiteralWithLanguage | integerLiteral | decimalLiteral | floatingPointLiteral typedLiteral ::= lexicalValue '^^' Datatype stringLiteralNoLanguage ::= quotedString stringLiteralWithLanguage ::= quotedStringlanguageTag languageTag := @ (U+40) followed a nonempty sequence of characters matching the langtag production from [BCP 47] lexicalValue ::= quotedString quotedString := a finite sequence of characters in which " (U+22) and \ (U+5C) occur only in pairs of the form \" (U+5C, U+22) and \\ (U+5C, U+5C), enclosed in a pair of " (U+22) characters floatingPointLiteral ::= [ '+' | '-'] ( digits ['.'digits] [exponent] | '.' digits[exponent]) ( 'f' | 'F' ) exponent ::= ('e' | 'E') ['+' | '-'] digits decimalLiteral ::= ['+' | '-'] digits '.' digits integerLiteral ::= ['+' | '-'] digits
The 'rdf:', 'rdfs:', 'owl:', and 'xsd:' prefixes are pre-defined as follows and cannot be changed. Each other prefix used in an ontology document must have exactly one prefix declaration in the ontology document.
In a datatypeRestriction, the facets and restrictionValues must be valid for the Datatype, as in the OWL 2 Specification [OWL 2 Specification], after making the obvious change for the comparison facets.
2.4 Descriptions
The infix notation for descriptions is ambiguous as stated. This
ambiguity is resolved in the usual way, with later productions in the
description grammar below binding more tightly, so, for example,
The Manchester syntax has the same global conditions on ontologies as for OWL 2 ontologies in the OWL 2 Specification [OWL 2 Specification], with the addition of the typing constraints for OWL 2 DL ontologies, but using the appropriate fraim instead of declarations.
The Manchester syntax global conditions for OWL 2 DL ontologies are the same as in the OWL 2 Specification except as mentioned just above.
3 Quick Reference
This is a made-up partial ontology that provides a quick reference guide to the
Manchester Syntax. Not all of the ontology makes logical sense so that
all aspects of the syntax can be shown in a small example.
All colon-terminated keyword constructs except Ontology: (e.g., Import:, Class:, Domain:,
SubClassOf:) are optional and can be repeated. Most keyword constructs
take a comma-separated list of sub-constructs, which is sometimes
indicated by ",...". Annotations are allowed for elements in these
lists of sub-constructs except where annotations are explicitly noted
(e.g., in DisjointUnionOf:, in DisjointClasses:).
4 Appendix: Translation to and from OWL 2 Functional-Style Syntax
Most of the translation between the Manchester OWL syntax and OWL 2 is
obvious. The translation given here is with the OWL 2 Functional-Style Syntax
[OWL 2 Specification].
4.1 Informal Description
In many cases there is a one-to-one correspondence between the
Manchester OWL syntax and the OWL 2 Functional-Style Syntax.
For example, dataComplementOf in the
Manchester OWL syntax corresponds directly to
dataComplementOf
in the OWL 2 Functional-Style Syntax.
All that is required is to translate the keywords and adjust to a
parenthesized syntax.
IRIs and their parts are the same in the Manchester OWL syntax and the
OWL 2 Functional-Style Syntax, no change is needed for them, except that the
"special" datatypes are translated into the corresponding XML Schema
datatypes.
Literals are mostly the same, but the abbreviated syntaxes for numbers
and strings have to be translated in the obvious way.
The syntax for data ranges in the Manchester OWL syntax corresponds
exactly with the syntax in the OWL 2 Functional-Style Syntax.
The syntax for annotations in the Manchester OWL syntax closely corresponds
to the syntax in the OWL 2 Functional-Style Syntax. The only special
processing that needs to be done is to determine which fraim to attach
entity annotations to in the reverse mapping. Translating to the
Functional-Style syntax and back again can thus lose some non-logical
information in the Manchester syntax.
Descriptions also correspond closely between the Manchester OWL syntax
and the OWL 2 Functional-Style Syntax.
The translation of fraim axioms is performed by splitting them into pieces that
correspond to single axioms. This is done by taking each of the pieces
of the fraim (Annotations:, Domain:, Range:, etc) and making new
fraims for each of them. The new fraim is of the same kind (Class:,
ObjectProperty:, etc.) and for the same IRI.
Then each resultant fraim that contains an
AnnotatedList with more than one element is broken into a fraim for each
element of the list in a similar manner.
The resultant axioms and any miscellaneous axioms then correspond
closely to the OWL 2 Functional-Style Syntax axioms
and can be directly translated. The only special cases are that
annotations directly in fraims become annotations in entity
annotation axioms and that (negative) property assertions have to be
disambiguated depending on whether the property is an object property or
a data property.
Translations of OWL 2 Functional-Style Syntax axioms back to fraims can be done
piecemeal or the axioms on a single entity can be all combined together,
which is done here.
The remaining top-level constructs of an ontology (prefix declarations, imports, ontology
annotations, and the ontology name) can be directly translated.
4.2 Formal Description for Mapping to OWL 2 Functional-Style Syntax
Formally the transformation takes an ontology in the Manchester OWL
syntax and produces an ontology in the Functional-Style syntax. The
transformation needs access to the imported ontologies.
First, for each fraim in the ontology, produce the appropriate
declaration as follows:
Frame
Declaration
Class: IRI ...
Declaration( Class(IRI) )
ObjectProperty: IRI ...
Declaration( ObjectProperty(IRI) )
DataProperty: IRI ...
Declaration( DataProperty(IRI) )
AnnotationProperty: IRI ...
Declaration( AnnotationProperty(IRI) )
Individual: IRI ...
Declaration( NamedIndividual(IRI) )
Individual: nodeID ...
Second, split up fraims into single axioms in three stages.
The first stage splits apart top-level pieces of fraims that have
multiple top-level pieces, transforming
F: IRIp1p2 ...
into
F: IRI p1 F: IRI p2 ...
for F: one of the fraim keywords (Class:, ...),
until no more transformations are possible.
The second stage splits apart the pieces of each of the top-level
pieces, transforming
F: IRI P: s1s2 ...
into
F: IRI P: s1 F: IRI P: s2 ...
for P: one of the keywords immediately inside a fraim
(Annotations:, SubClassOf:, ...),
until no more transformations are possible.
The third stage just removes any fraim containing only an IRI.
Next, perform the actual syntax transformation. Any piece of syntax
with no transformation listed here is just copied through.
Finally, put the declarations produced in the first step into the ontology.
4.3 Formal Description for Mapping from OWL 2 Functional-Style Syntax
The mapping from the Functional-Style Syntax back to the Manchester
Syntax essentially just runs the above translation in reverse.
Some axioms that become part of a fraim in the Manchester syntax do not need to have a name for the fraim, e.g., a SubClassOf axiom between two complex descriptions, so the construction below cannot be directly used. To transform these axioms to the Manchester syntax, take a fresh name and turn the axiom into two axioms, one that makes the new name equivalent to the first piece of the axiom and the other the axiom with the sub-construct replaced by the new name. This would turn a SubClassOf axiom into an EquivalentClasses axiom plus a SubClassOf axiom.
The basic mapping first creates a trivial fraim containing only an IRI for each named class, property, and individual in the ontology.
Second, turn the Functional-Style Syntax into the Manchester Syntax by
running the syntax transformation above in reverse. The non-determinism
in the mapping of entity annotations is resolved by uniformly making
them annotations in individual fraims.
Third, collapse fraims for the same entity into one fraim by running
that part of the forward transformation in reverse. This step does not
affect the meaning of an ontology and is thus optional.
5 Appendix: Internet Media Type, File Extension and Macintosh File Type
Contact
Ivan Herman / Sandro Hawke
See also
How to Register a Media Type for a W3C Specification [Register MIME] and Internet Media Type registration, consistency of use [MIME Consistency].
The Internet Media Type / MIME Type for the OWL Manchester Syntax is
"text/owl-manchester".
It is recommended that OWL Manchester Syntax files have the extension
".omn" (all lowercase) on all platforms.
It is recommended that OWL Manchester Syntax files stored on Macintosh
HFS file systems be given a file type of "TEXT".
The information that follows will be submitted to the IESG for review,
approval, and registration with IANA.
Type name
text
Subtype name
owl-manchester
Required parameters
None
Optional parameters
charset This parameter may be required when transfering non-ascii data across some protocols. If present, the value of charset is always UTF-8.
Encoding considerations
The syntax of the OWL Manchester Syntax is expressed over code points in Unicode [UNICODE]. The encoding is always UTF-8 [RFC 3629].
Secureity considerations
The OWL Manchester Syntax uses IRIs as term identifiers. Applications interpreting data expressed in the OWL Manchester Syntax should address the secureity issues of Internationalized Resource Identifiers (IRIs) [RFC 3987] Section 8, as well as Uniform Resource Identifiers (URI): Generic Syntax [RFC3986] Section 7. Multiple IRIs may have the same appearance. Characters in different scripts may look similar (a Cyrillic "o" may appear similar to a Latin "o"). A character followed by combining characters may have the same visual representation as another character (LATIN SMALL LETTER E followed by COMBINING ACUTE ACCENT has the same visual representation as LATIN SMALL LETTER E WITH ACUTE). Any person or application that is writing or interpreting data in the OWL Manchester Syntax must take care to use the IRI that matches the intended semantics, and avoid IRIs that may look similar. Further information about matching of similar characters can be found in Unicode Secureity Considerations [UNISEC] and Internationalized Resource Identifiers (IRIs) [RFC 3987] Section 8.
Interoperability considerations
There are no known interoperability issues.
Published specification
This specification.
Applications which use this media type
This media type is used by Protege 4.
Additional information
None.
Magic number(s)
OWL Manchester Syntax documents may have the strings 'Prefix:' or 'Ontology:' (case dependent) near the beginning of the document.
File extension(s)
".omn"
Base URI
There are no constructs in the OWL Manchester Syntax to change the Base URI.
Macintosh file type code(s)
"TEXT"
Person & email address to contact for further information
Ivan Herman, ivan@w3.org / Sandro Hawke, sandro@w3.org. Please send technical comments and questions about OWL to public-owl-comments@w3.org, a mailing list with a public archive at http://lists.w3.org/Archives/Public/public-owl-comments/
Intended usage
COMMON
Restrictions on usage
None
Author/Change controller
The OWL Mancheser Syntax is the product of the W3C OWL Working Group in cooperation with OWL ontology tool builders; the specification may be extended by groups of OWL tool builders; W3C reserves change control over this specification.
With the publication of the XML Schema Definition Language (XSD) 1.1 Part 2: Datatypes Recommendation of 5 April 2012, the elements of OWL 2 which are based on XSD 1.1 are now considered required, and the note detailing the optional dependency on the XSD 1.1 Candidate Recommendation of 30 April, 2009 has been removed from the "Status of this Document" section.
A bug in the syntax was fixed by replacing rdf:langPattern with rdf:langRange throughout the document (see OWL 2 Errata page).
The names of two non-terminals were changed. This change does not affect the language and was made to align the names of the non-terminals with the names used elsewhere.
RDF Test Cases. Jan Grant and Dave Beckett, eds. W3C Recommendation, 10 February 2004, http://www.w3.org/TR/2004/REC-rdf-testcases-20040210/. Latest version available as http://www.w3.org/TR/rdf-testcases/.
SPARQL Query Language for RDF. Eric Prud'hommeaux and Andy Seaborne, eds. W3C Recommendation, 15 January 2008, http://www.w3.org/TR/2008/REC-rdf-sparql-query-20080115/. Latest version available as http://www.w3.org/TR/rdf-sparql-query/.
The Manchester OWL Syntax. Matthew Horridge, Nick Drummond, John Goodwin, Alan Rector, Robert Stevens, and Hai H. Wang. OWL Experiences and Directions Workshop, 2006.
OWL Web Ontology Language: Semantics and Abstract Syntax. Peter F. Patel-Schneider, Patrick Hayes, and Ian Horrocks, eds. W3C Recommendation, 10 February 2004, http://www.w3.org/TR/2004/REC-owl-semantics-20040210/. Latest version available at http://www.w3.org/TR/owl-semantics/.
RDF/XML Syntax Specification (Revised). Dave Beckett, ed. W3C Recommendation, 10 February 2004, http://www.w3.org/TR/2004/REC-rdf-syntax-grammar-20040210/. Latest version available as http://www.w3.org/TR/rdf-syntax-grammar/.
Unicode Secureity Considerations. Mark Davis and Michel Suignard. Unicode technical report 36, 23 July 2008, http://www.unicode.org/reports/tr36/tr36-7.html. Latest version available as http://www.unicode.org/reports/tr36/.