EntityType refers to the type of entities you want included in the results - including requirements, script, automated tests, script assignments, automated test assignments, incidents and packages.
See the Types topic for details on the list of supported type values.
All entities of type requirement:
EntityType = Requirement
All entities of type script or script assignment:
EntityType = Script OR EntityType = ScriptAssignment
Which can also be written as:
EntityType IN [Script, ScriptAssignment]
All entities which are not packages:
EntityType != Package
Entity, Package, Relationship, Run