BIP 8: Require the bit to be set during LOCKED_IN

bip-0008.mediawiki

@@ -72,8 +72,9 @@ for the purposes of this proposal, and support two future upgrades for different
 When a block nVersion does not have top bits 001, it is treated as if all
 bits are 0 for the purposes of deployments.
 
-Miners should continue setting the bit in LOCKED_IN phase so uptake is visible, though this has no effect on
-consensus rules.
+Miners must continue setting the bit in LOCKED_IN phase so uptake is visible and acknowledged.
+Blocks without the applicable bit set are invalid during this period.
+For flexibility, this rule does NOT require the top 3 bits to be set any particular way.
 
 ===New consensus rules===