This should't be failed:

<input autocomplete="none" />

Unfortunately, the only way I can think that we allow this is to create a list of synonyms that someone might mistakenly be using, instead of using "on" or "off" which are actually allowed. So things like "none", "false", "true", "disabled", "enabled", "undefined", "null", etc. They'll need to be in a check option, so that this can be configured.

I don't think we should even bother to report them as incomplete. Passing the rule is fine in this scenario.