The interrobang is just a ligature for !?, the love point is just a ligature for <3, the sarc mark is just a ligature for /s.<p>Friendly period is a waste, just don’t type a period, same effect<p>The goals of the question comma and exclamation comma can be achieved with existing constructions - how so? Like this! - that are just as parsimonious.<p>Irony, rhetorical question, and snark mark are <i>actively</i> bad: all three symbols destroy the ambiguity that is necessary for the device to function.<p>The Authority mark already exists[1].<p>Elrey and Acclamation seem to be fairly niche variations on the purpose of the standard exclamation mark - maybe a combining diacritic mark is the solution!̇ Typists of languages other than English are already there, just waiting to welcome you!̫̑<p>That leaves Certitude and Doubt. <i>Certainly</i> their case is the strongest, as they replace entire words. <i>Perhaps</i> using entire words is a good thing, though; the spectrum of certitude might be richer than the all-or-nothing binary choice offered by two characters…<p>1: The current form has the distinct advantage of actually providing some information about the authority being claimed.