Test Drive 160922 Eka Harkka | Page 72

The Namespaces Node Click on the Namespaces node. Here you will find the different namespaces defined in the schema file. A namespace is a way of grouping related fields and avoid name collision between fields with identical names. You can add a namespace either by creating a totally new namespace (right-click on the Namespaces node and select Add namespace from the pop-up menu), or you can import a namespace that somebody else has created (right-click on the Namespaces node, and select Import namespace from file from the pop-up menu). Note, however, that creating a new namespace is normally done to create a new set of fields for a particular purpose. If you need to create one new field, you should create your own namespace if possible, since existing namespaces are locked per se. However, we allow you to add fields (that are missing) to existing namespaces. Make sure that the field you add conforms to the exact specification of the namespace in question. Also, if you discover that you organization needs to create a number of new fields for a use that is not covered in the included namespaces, you should create your own namespace to insert these new fields. A namespace will often contain information about who created it and what it should be used for. The namespace is identified by a URI (often on the format http://ns.domain.com/namespace/version/). Note that the URI doesn’t have to be a valid web address, but the identifier must be unique. Use a domain name that you own when creating a new namespace. Alternatively, use purl.org to create vendor-in­ dependent URIs. 72 FotoWare