Ah, I missed that in the documentation. It's still not pretty, but at least the list is complete now.
Thanks a lot.
For reference, this is the code I am now using:
var filter = "IncludedTypes=Action,Activity,ActivityPartition,ActivityRegion,Actor,Artifact,Association,Boundary,Change,Class,Collaboration,Component,Constraint,Decision,DeploymentSpecification,DiagramFrame,EmbeddedElement,Entity,EntryPoint,Event,ExceptionHandler,ExitPoint,ExpansionNode,ExpansionRegion,GUIElement,InteractionFragment,InteractionOccurrence,InteractionState,Interface,InterruptibleActivityRegion,Issue,Node,Note,Object,Package,Parameter,Part,Port,ProvidedInterface,Report,RequiredInterface,Requirement,Screen,Sequence,State,StateNode,Synchronization,Text,TimeLine,UMLDiagram,UseCase";