Wikipedia editor and computer software engineer Brian Henderson has changed over 40,000 instances of the phrase comprised of in the site's articles. He was on the BBC Radio 4 Today programme this morning (listen to the interview here - scroll to 1:21:45). Henderson describes himself as a perfectionist and a grammarian. Most Wikipedia article writers accept his corrections, although a minority, he says, are very attached to their grammar and they way they speak. He spends between an hour and two hours a week correcting the grammar in Wikipedia articles, although he has written a software program to take the tedium out of doing the same thing again and again. He changes 'school districts are comprised of schools' to 'school districts operate schools' , for instance (although, he's changed the meaning as well as the grammar there, I'd say). Comprised of is just one of hundreds of pet peeves he has, and he says he could spend 24 hours a day correcting them all. We all have pet peeves, but my attitude is - life's too short! James Naughtie, Today host, probably feels the same - after the interview he implied he wouldn't like to be stuck on a train with Henderson for any length of time.