About query form filters
A filter is a set of criteria for retrieving a collection from a middle-tier IDO. You create a filter for an IDO by creating a query form associated with the IDO. Afterwards, you can use the query form to create additional filters for the same IDO. Filters must contain primary criteria (required properties with operators and values in an AND relation). They can also contain additional criteria (optional properties with operators and values in an AND or an OR relation).