Patrik, > I think it is important to not restart discussions already held regarding different requirements on identifiers, requirements that in turn lead to various alternatives on how they are allocated, managed and resolved. Understood. Thanks. > I do not think one can have one identifier that fits all. Instead multiple kind of identifiers are needed. Because of requirements on uniqueness (absolute, low risk of collisions or not needed at all), persistence, human readable/understandable, whether allocation and resolution should be designed for read (lookups) or write (allocation), what the identifier is to be used for (see id/loc discussions). Agreed. Jari