I don't think they are rare either!
Dave, I know what you mean. If I could just give the entire world a class.... I would teach them the difference between it's and its and they're, there, and their, and too, to, and two.... I'd also let them know that a lot is two words, that light is not spelled lite, night is not spelled nite, through is not spelled thru, and every word that ends in s does NOT have to have an apostrophe!!! 80's, vacuum's car's... it drives me crazy, it is for ownership or contractions, not plurals!! And while we are at it, let's teach them that vacuum is not vacumne or vaccum.... Kirby is not Kerby or Kurby and Eureka is not Eurica... I see that on Craig's List all the time!