The high court dismissed the Philip Morris appeal without issuing an opinion, ending the third appeal the company had secured before the Supreme Court in its fight to reign in an award by an Oregon jury."Awright, class," as my ninth grade science teacher, Papi Castro, used to say in his mellifluous Bronx accent, "get dis, and geddit good": a "rein" is a leather strap used to control a horse's movement, and to "rein in" means to check or control something; to "reign" (the "g" is pronounced like that in "gnu") is to possess sovereign power, as a monarch. So, when Philip Morris petitioned the Supreme Court to limit a jury award, it sought to rein, not reign, it in.
I've often seen "reign" used where its homonym, "rein", is intended. This is likely because, in one sense, the words are near synonyms. Used as a verb, "rein" means to control; to "reign" is also to exercise control. One expression in which "reign" shows up frequently is "to give [or allow] free reign [sic]." In this instance, "rein" and "reign" mean almost opposite things, since a rider who gives "free rein" is allowing the horse to proceed at its own chosen speed rather than exercising control, while a monarch with "free reign" would, I suppose, have absolute power. So, it's "free rein" not "free reign". Geddit?
Update: twif offers the following: "claude, this is what happens when you replace copy editors with word's spell check function." An astute observation, indeed. Still, it helps to have writers who know the meanings of the words they use.
P.S. for twif: the kid looks great.