On Mon, 2012-09-10 at 15:08 +0200, Ferrandis, Ludovic wrote: As far as I can tell the code at least is consistent. GetProp returns an error if a property is not defined, even if it is mandatory and GetAll returns only defined properties, omitting undefined properties marked as mandatory in the documentation and the specs. ListChildren and Search behave in the same way. What is confusing, as you rightly point out, is that an application can potentially receive a property not found error when attempting to retrieve a mandatory property, which according to the specs, should exist. We could leave things the way they are and let applications trap the errors and provide defaults, but since one of the motivations behind dLeyna is to make life easier for DLNA applications, we should probably change the code to behave as you suggest, i.e. to provide default values for missing mandatory properties. However, remember that: 1. There are different types of mandatory properties and we would need to provide sensible default values for all properties. It may be more complicated than simply returning an empty string. 2. The behaviour of GetAll, Search and ListChildren must remain consistent. So if GetAll starts returning default values for undefined mandatory properties, Search and ListChildren must do so as well, unless of course the caller has chosen to filter them out. I think this should mostly come for free if we add our code to the right place, but it still needs to be tested. Regards, Mark