ReferenceCount was the core class in the smart pointer system that Rosetta3 used up until 2015. Nearly every class in Rosetta ultimately inherits from this class - by that measure it is our most important class. Luki Goldschmidt transitioned us to a newer smart pointer system, which obviated the purpose of the old ReferenceCount as the holder class for the smart pointer system how-many-point-at-me variable. The class remains as an empty class. This is partly because, as the ultimate inheritance root of almost all classes, it was too hard to remove. It offers a remaining benefit to the Pose DataCache, as a common reference point for all classes that can be put into said DataCache.