  This paper discusses several issues around Relational Quantum Mechanics.
First, I discuss possible ontologies underlying the interpretation, before
settling on the hypothesis that RQM follows from contextuality of measurements,
due to quantum measurements changing the system measured. I then examine how
the approach to quantum logic in the consistent histories formalism can be used
to clarify which information about a system can be shared between different
observers. Finally I discuss the similarities and differences between special
relativity and RQM.
