3.2.4.2 Remote Indexing Service Catalog Query Messages
With the exception of CPMGetRowsIn/CPMGetRowsOut and CPMFetchValueIn/CPMFetchValueOut, there is a one-to-one relationship between Content Indexing Services Protocol messages and higher-layer requests. For the two exceptions previously mentioned, there can be multiple messages generated by the client to either satisfy size requirements or retrieve a complete property. The higher layer typically keeps track of all query-specific information (such as cursor handles opened, legal values for bookmark and chapter handles, and _wid values for deferred property values) and also tracks if the client is in a connected state, but this is not enforced in any way by the client.
The client portion of the diagram in section 3 illustrates this sequence for a simple indexing service query.