Yeah, NIP04 payloads include `?iv=` near the end. But the bigger difference is NIP 59 uses kind 1059 and NIP 04 uses kind 4 

 But the encrypted content of a custom list can't be distinguished that way. 

 No? Isn't nip44 base64 encoded? `?` and `=` aren't valid b64 characters, so I think the check still works. 

 Yes *that* check works. Checking the kind doesn't work. 

 Oh, yeah, sure