... not require a social element). Rules of etiquette do not apply ... a social element.
4. Rules of etiquette will not apply ... or purely manners.
5. Rules may or may not apply ...
-so if you fail a sufficient condition, the rule "goes away" ?
-but if you satisfy a necessary condition, the rule also "goes away" ?
-you would not want to rely on a contrapositive of any of these rules in these two situations above?