Under what circumstances does Muse produce an “Unsupported Query” error?

Here are some details about the query remapping mechanism in Muse: if a search on one or more search attributes is performed on a Muse Source Package, the ICE Search module analyses the Source Package CPB (capabilities) file and all the search attributes included in query which are not present in the CPB file are remapped to the default attribute. The default attribute to be used for unsupported search attributes is defined in the Source Package PMF (PreMappingFile) file.