Results > Manipulate the Results Set > Combine Parameter > ReferenceTypeFields

For this option, ReferenceTypeFields is a plus-, space-, or comma-separated list of ReferenceType fields. If a query produces several results that contain the same value in one or more of the specified ReferenceType fields, IDOL server returns only the most relevant result. If several results have the same relevance, the result with the highest DOCID returns (unless you enable a Sort option that overrides this).
For example:
http://IDOLhost:port/action=Query&Text=The Moonstone&Combine=DRETITLE
In this example, if several results contain the same value in the DRETITLE field, it displays only the result that has the highest relevance to the query text.
When you combine using a ReferenceType field, IDOL server automatically uses all the fields that you list in the configuration file in the same PropertyFieldCSVs parameter as this field. To ensure that IDOL server combines using only the specified field, you must set up an individual field process to identify this field as a ReferenceType field.
If you want to use multiple ReferenceType fields to combine, you may want to create a process that identifies all of these fields as ReferenceType.
Related Topics 
For example:
In this example, if you set Combine to DREREFERENCE, IDOL server combines using the DREREFERENCE and url fields. If you set Combine to DRETITLE, it uses only the DRETITLE field to combine.
Multiple Options
You can combine the Simple and FieldCheck options, in which case you must specify Simple first. For example:
If you set Combine to referenceTypeFields, you cannot combine the fields with another Combine option.