You would have thought that, by now, everyone who was both eligible and keen to join would have already done so!
If Registration is such a fantastic idea, I wonder why "they" don't just get on with it (that is, drop the "Voluntary" bit, and be done with it)?

They should be OK now that the Royal Corps of Transport has been
subsumed by the Royal Logistic Corps.*
Meanwhile, me and Billy are still having problems coming up with a catchy name for the Club of our own.
Is the Ar-riyadh Biomedical Engineering Club still thriving, by the way, Neil? Or was that yet another
damp squib? 
*
Also known as the "Really Large Corps".