OWL - Linked Data: A Geographic Perspective - page 167

URL (Uniform Resource Locator) needs to be changed, only one change need be
made rather than strings needing to be changed throughout the document.
There are a number of standard namespaces for ontologies:

rdf http://www.w3.org/1999/02/22-rdf-syntax-ns#

rdfs http://www.w3.org/2000/01/rdf-schema#

xsd http://www.w3.org/2001/XMLSchema#

owl http://www.w3.org/2002/07/owl#

Any ontology editor will provide these for you, but it is worth being able to
recognize them. To use definitions originally coined in other ontologies, you may
wish to import them into your ontology. Importing an ontology means that you take
on board, and agree with, all the statements in the third-party ontology, so you may
wish to segment it first and only take the subset of statements with which you agree.
This will also make the ontology smaller.
The following is an example of how Merea Maps' ontology might begin:

1. Prefix: < http://mereamaps.gov.me/topt/ >
2. Prefix: dc: < http://purl.org/dc/elements/1.1/ >
3. Prefix: rabbit: < http://www.ordnancesurvey.co.uk/ontology/Rabbit/
v1.0/Rabbit.owl/ >
4. Ontology: < http://mereamaps.gov.me/topo > < http://mereamaps.gov.me/
topo-v1 >
5. Import: < http://www.ordnancesurvey.co.uk/ontology/Rabbit/v1.0/
Rabbit.owl >
6. Import: < http://purl.org/dc/elements/1.1/ >
7. Annotations: dc:rights “Merea Maps 2011”,
8. dc:title “Topography”,
9. rabbit: purpose “To describe the administrative
geography of Merea and the topological relationships between them.”
10. rabbit: scope “All levels of administrative area that occur in
Merea, their sizes, point locations, the topological relationships
between areas of the same type. Authorities that administer the regions
are not included, nor are the spatial footprints of the regions.”
11. owl:versionInfo “v1”
12. AnnotationProperty: dc:rights
13. AnnotationProperty: dc:title
14. AnnotationProperty: rabbit:purpose
15. AnnotationProperty: rabbit:scope
16. AnnotationProperty: owl:versionInfo

The line numbers in this code are for reference only and not part of the actual
ontology. As we can see, the ontology begins by stating the prefixes used: first, the
main ontology, which has no prefix; then the prefix dc for the Dublin Core ontology,
which is a well-known standard ontology that provides annotation properties like
title , rights , and coverage ; and the prefix rabbit for the CNL ontology that
includes annotation properties linked to the ontology authoring method described
in Chapter 10, for example, to include annotations on the scope and purpose of the