"During a 1632-1638 epidemic of possession of Ursuline nuns at a convent of Loudun in Poitou-Charentes region of western France, it became necessary to exorcise the Mother Abbess, who’s demon clearly had a better grasp of Latin syntax than his exorcists, who mocked an apparent grammatical error on the part of the devil, that is, until the lead exorcist Father Barre pointed out that technically, while undoubtedly diabolical, the possessing demon was actually syntactically correct."
Yes indeed, they are well known. Their names are Orobas, Corson and Damon.
These three succubi haunt the dreams of men WHO dream of 19th century schoolmasters, gowned and mortar-boarded, wielding long canes as they pound the rules of grammar into recalcitrant schoolboys. Until they are exorcised thee three overrun the minds of the possessed who spend their days watching the lips of their interlocutors waiting for the merest grammatical lapse so that they can pounce and correct it.
Now that we have entered the age of the Internet Orobas, Corson and Damon are gleefully working their mischief around the globe, claiming victims by the thousands.
The good news is that they can be exorcised by repeating their names a thousand times. But, since it would take so long to keep repeating Orobas, Corson, Damon, it is sufficient use their initials. OCD, OCD, OCD...