Why not the following in case the record schema is specified? Client requests recordSchema A, Server responds with one of the following: 1. A 2. Sorry I don't have A 3. extraRequest Data: We have B which could be used instead of A Especially in an environment with mixed schemas this is less complicated then asking for "if you don't have this schema, then give me that schema" Theo >>> [log in to unmask] 12/17 10:15 >>> From: "Robert Sanderson" <[log in to unmask]> > The value of records/record/recordSchema must be the URI for the > recordSchema in the request unless one of the following conditions occurs: > > 1. The request did not specify a recordSchema and the server has chosen a > default, in which case it is the URI for this default. > 2. The record is a surrogate diagnostic, in which case it is the URI for > the diagnostic schema. > 3. The response semantics have been modified via a profiled extension in > extraRequestData. 1 and 2 yes. Instead of 3, I'd prefer that if a client has, let's say, a list of schemas and he want the server to choose one from that list, he should leave the parameter blank and we should define an extraRequestData for this purpose. I'd like us to avoid allowing normative semantics to be modifiable by extraDataRequest. I agree that the parameter doesn't have to identify an xml schema, for example it could identify the dcx definition "records are encoding according to the DCMI guidelines and contain terms from the dc and dcterms namespaces.; records may contain terms from other namespaces.... etc" But if that parameter is supplied in the request, than that same parameter must be supplied in the response (unless a diagnostic) that is, the server is not allowed to be helpful by identifying a real xml schema instead. Similarly for the "anythingGoes" schema that Mike suggests -- if that's the value of the request parameter then it must be the value of the response parameter. Though, for "anythingGoes" the client is better of omitting the parameter, and then the server may tell him the real schema. --Ray