Hmm …

… An English Teacher's Incorrect Correction of a Trump Letter Illustrates His Critics' Reflexive Condescension - Hit & Run : Reason.com.  (Hat tip, Dave Lull.)

The staffer who wrote this form letter can hardly be faulted for following the federal government's style manual, even if you and I might not like the rules it contains. Nor did he do anything wrong by referring to the Justice Department's proposed ban on bump stocks as a "rule," a term that seems to have puzzled Mason. 

It certainly illustrates that if you're going to be pedantic, make sure you know what you're talking about.