RFC2141 just defines a way to make ids in a non conflicting way. you don't need to use one of the registered namespaces to use URN, you can make up your own an

RFC2141 just defines a way to make ids in a non conflicting way. you don't need to use one of the registered namespaces to use URN, you can make up your own and you don't need to register them for them to be useful. at my company we use urn:l6: namespace (company name is L6) whenever we need ids. it very useful especially when you use barcodes, rfid, etc..