Clarify ignore for SIG_INPUTS

Author: robwoodgate

11.md

@@ -112,7 +112,7 @@ Signatures are stored in `P2PKWitness` objects and are provided in either each `
 
 The `signatures` are an array of signatures in hex and correspond to the signatures by one or more signing public keys.
 
-To facilitate the signing of multi-party `SIG_ALL` transactions, the SHA256 digest of the message to be signed can be stored in the optional `P2PKWitness.digest` of the `Proof` to be signed. Wallets SHOULD sign a `SIG_ALL` proof over this digest, if present.
+To facilitate the signing of multi-party `SIG_ALL` transactions, the SHA256 digest of the message to be signed can be stored in the optional `P2PKWitness.digest` of the `Proof` to be signed. Wallets SHOULD sign a `SIG_ALL` proof over this digest, if present, and ignore it entirely for `SIG_UNPUTS` proofs.
 
 #### Signature flag `SIG_ALL`