Good morning Mark,
> The idea is simple: instead of requiring that the final parameter on the
> stack be zero, require instead that it be a minimally-encoded bitmap
> specifying which keys are used, or alternatively, which are not used and must
> therefore be skipped. Before attempting
When Satoshi wrote the first version of bitcoin, s/he made what was almost
certainly an unintentional mistake. A bug in the original CHECKMULTISIG
implementation caused an extra item to be popped off the stack upon completion.
This extra value is not used in any way, and has no consensus
