On Tue, Jan 31, 2012 at 7:22 PM, Matt Corallo <bitcoin-list@bluematt.me>wrote:

>
> All that said, I dont think its an ideal solution, depending on the
> names of variables to provide information is ugly.  If anyone has a
> better idea on how to do backward compatibility, please suggest it.
>

I like the mustimplement: idea, though I'd recommend a shorter
(abbreviated) prefix, to keep URL sizes small for QR codes and such,

Wladimir