Hi Snarf,
The Typeref reference is simply the name an TypeDef or ClassDef object. All basic types reside in the system volume, pwrs, and types are defined under the Type hierarchy and have for some reason a $ sign in the name. Thus the name of the TypeDef will be something like pwrs:Type-$Float32.
The DsTrend class is defined with a ClassDef object in the base volume, pwrb, and as it is a class it is defined under the Class hierarchy. The name of the ClassDef is pwrb:Class-DsTrend, and the name of the fast curve classdef is pwrb:Class-DsFastCurve.
/Claes