Complex sentence: All those joining the scheme must revalidate their registration every 3 years this involves keeping a journal planner of continuing professional development as well as other activies that demonstrate they have kept their professional body of knowledge current.
Split into simpler sentences: All those joining the scheme must revalidate their registration every 3 years. This involves keeping a journal planner of continuing professional development as well as other activies that demonstrate they have kept their professional body of knowledge current.