  We discuss some difficulties that arise in attempting to interpret the
Page-Wootters and Internal Quantum Reference Frames formalisms, then use a
'final measurement' approach to demonstrate that there is a workable
single-world realist interpretation for these formalisms. We note that it is
necessary to adopt some interpretation before we can determine if the
'reference frames' invoked in these approaches are operationally meaningful,
and we argue that without a clear operational interpretation, such reference
frames might not be suitable to define an equivalence principle. We argue that
the notion of superposition should take into account the way in which an
instantaneous state is embedded in ongoing dynamical evolution, and this leads
to a more nuanced way of thinking about the relativity of superposition in
these approaches. We conclude that typically the operational content of these
approaches appears only in the limit as the size of at least one reference
system becomes large, and therefore these formalisms have an important role to
play in showing how our macroscopic reference frames can emerge out of wholly
relational facts.
