diff --git a/bip-tapscript.mediawiki b/bip-tapscript.mediawiki
index a325573e..1ace177b 100644
--- a/bip-tapscript.mediawiki
+++ b/bip-tapscript.mediawiki
@@ -67,7 +67,7 @@ Validation of such inputs must be equivalent to performing the following steps i
===Script execution===
The execution rules for tapscript are based on those for P2WSH according to BIP141, including the OP_CHECKLOCKTIMEVERIFY
and OP_CHECKSEQUENCEVERIFY
opcodes defined in BIP65 and BIP112, but with the following modifications:
-* '''Disabled script opcodes''' The following script opcodes are disabled in tapscript: OP_CHECKMULTISIG
and OP_CHECKMULTISIGVERIFY
. The disabled opcodes behave in the same way as OP_RETURN
, by failing and terminating the script immediately when executed, and being ignored when found in unexecuted branch.
+* '''Disabled script opcodes''' The following script opcodes are disabled in tapscript: OP_CHECKMULTISIG
and OP_CHECKMULTISIGVERIFY
['''Why are ]OP_CHECKMULTISIG
and OP_CHECKMULTISIGVERIFY
disabled, and not turned into OP_SUCCESSx?''' This is a precaution to make sure people who accidentally keep using OP_CHECKMULTISIG
in Tapscript notice a problem immediately. It also avoids the complication of script disassemblers needing to become context-dependent.. The disabled opcodes behave in the same way as OP_RETURN
, by failing and terminating the script immediately when executed, and being ignored when found in unexecuted branch.
* '''Consensus-enforced MINIMALIF''' The MINIMALIF rules, which are only a standardness rule in P2WSH, are consensus enforced in tapscript. This means that the input argument to the OP_IF
and OP_NOTIF
opcodes must be either exactly 0 (the empty vector) or exactly 1 (the one-byte vector with value 1)['''Why make MINIMALIF consensus?''' This makes it considerably easier to write non-malleable scripts that take branch information from the stack.].
* '''OP_SUCCESSx opcodes''' As listed above, some opcodes are renamed to OP_SUCCESSx
, and make the script unconditionally valid.
* '''Signature opcodes'''. The OP_CHECKSIG
and OP_CHECKSIGVERIFY
are modified to operate on Schnorr public keys and signatures (see bip-schnorr) instead of ECDSA, and a new opcode OP_CHECKSIGADD
is added.