When using Cityworks asset management system integrated with ArcGIS it's necessary to add a definition query to layers in order to exclude "retired" assets from the map/layer (by a Status attribute). This is necessary since retired assets cannot be removed from their feature class since that would break any relationships between them and previous work order histories. This works fine, what is a problem though is that this does not work for object classes as no definition query capability is possible. I think the usefullness of this capability is greater than this specific need. Please add the ability to define definition queries for object classes.