>> But I don't have any strong opinion about that. I'm open to suggestions. > > Don't ask for suggestions before consulting CodingGuidelines, > perhaps? I think that Patrick was unsure about adding the external parentheses to make it look like [(--format=(keyvalue|nul) | -z)]. CodingGuideLines is not explicit about that specific case of having alternate flags with nested alternate arguments, but I don't see a reason for using parentheses as it isn't ambiguous...