When creating an OWL ontology in Protege, you are asked early on to define the URI for that ontology, replacing the default of http://www.owl-ontologies.com/Ontology#######.owl with your own text. But what constitutes the most useful URI for your purposes? This page will serve as a common place to document the best practices for choosing a URI for your ontology so that users of your ontology are best served. Tied up in this subject is the issue of how to distinguish new versions of your ontology from old versions, and how to do so in a way that users can take advantage of your new versions in the easiest manner possible.    (9YA)

To begin, let's be clear on the difference between a URI and URL. URI stands for Uniform Resource Identifier, and is sometimes confused by newbies with a URL, Uniform Resource Locator. Wikipedia describes the difference in the following way:    (9YB)

"A URI can be classified as a locator or a name or both. A Uniform Resource Locator (URL) is a URI that, in addition to identifying a resource, provides means of acting upon or obtaining a representation of the resource by describing its primary access mechanism or network "location". For example, the URL http://www.wikipedia.org/ is a URI that identifies a resource (Wikipedia's home page) and implies that a representation of that resource (such as the home page's current HTML code, as encoded characters) is obtainable via HTTP from a network host named www.wikipedia.org."    (9YC)

The following considerations should factor into your selection of a good URI:    (9YD)

The following considerations should factor into your selection of a good way to choose URLs    (9YI)