Distinguish between standard and consensus rules about zips HOT 1 CLOSED

I've decided that Zcash will not add any standard rules, beyond its additional consensus rules. It will retain all of the standard rules of Bitcoin, except that where a Bitcoin consensus rule is loosened (e.g., allowing txns with zero transparent inputs iff there is a JoinSplit), the corresponding standard rule is set to the consensus rule.

Note that the Bitcoin documentation is generally quite poor on specifying standard rules; it specifies the standard scripts, but some of the other standard rules are not specified anywhere but the Bitcoin Core implementation (and of course mining software can impose its own arbitrary additional rules). The Zcash spec needs to explicitly call this out as a problem.

from zips.