That is tied to the alps spec. I can alias it return_type, but I only would ever really consume it as rt. We discussed a while back whether we should change some naming conventions in the YAML resource descriptor document. For the meantime, I had left that more explicit that way. If we decide to rename things in the the yaml, then we could name this `return_type` and alias it as `rt`. But for the moment, would prefer to keep things tied to ALPS a little closer and revisit this when we start using it. Thougths?