4.4.2 Namespace purpose
Namespaces have little purpose as long as documents are not exchanged between repositories. The main purpose of namespaces it to allow import/export (replication) of documents between repositories. If there wouldn't be namespacess, the document IDs between the repositories would not be unique and hence there would be conflicts. For example, in both repositories there might be a document with ID 55, though these would be different documents. It would of course be possible to assign new IDs to documents upon import, but then the identity of the original document would be lost, which would make subsequent 'update' imports difficult, and also requires updating links in all document content (which would mean the import tool has to understand the document formats).