In high school I read about an ancient Greek philosopher who developed a punctuation mark that signified "or so it seems to me at the moment." This made it easy for this philosopher to qualify his statements. I just can't remember his name.
Sextus Empiricus, a Pyrrhonian Skeptic living probably in the second or third century CE, many of whose works survive, including the Outlines of Pyrrhonism, the best and fullest account we have of Pyrrhonian skepticism.
The "skeptical grammar", developed by Sextus Empiricus, ends every preposition with "so it seems to me at the moment".
He gives a negative account of the knowledge of his time, doubting everything including God and the possibility of knowledge.
Since he used the phrase so frequently, it is rather probable that he invented an abbreviation. Readers fluent in Greek may here Sextus (Empiricus.),Immanuel Bekker: "Sextus Empiricus" (1842) find out what he used to express his sceptical attitude.
Sources: http://www.philosophenlexikon.de/sextus-empiricus/ https://quizlet.com/118873950/soccio-archetypes-of-wisdom-ch-10-the-skeptic-david-hume-flash-cards/ https://plato.stanford.edu/entries/sextus-empiricus/ https://de.wikipedia.org/wiki/Sextus_Empiricus