Version 1.1, 12th January 2004
The Explain record for an SRW server is a means of recording the facilities available in the server. It is used by clients to self configure, such that they may then fully interoperate with the server. The record is in XML and follows the ZeeRex Schema.
There are two methods for getting the explain record. The first method is via the 'explain' operation, and carries the common parameters of stylesheet, version and extraRequestData, along with the recordPacking parameter to instruct the server how to escape the record in the response. The response carries version, extraResponseData and a record field which holds the actual explain record.
The second method is a parameterless GET http request at the base URL for the service. This can be considered an SRU request (and hence have a default recordPacking of 'xml'), with no extraRequestData and leaving it up to the server to determine the version of the response. Otherwise, the response is identical to an SRU explainResponse message.
The ZeeRex schema, also used for describing Z39.50 servers, is fully described at the http://explain.z3950.org/ website. The SRW specific information is available at http://explain.z3950.org/srw/.