To The New Yorker(again).

"My dears,
Please consider the following 2 sentences:

1) "P.p.m. is the usual abbreviation for 'parts per million'."

2) " 'Parts per million' is usually abbreviated p.p.m. "

These are equivalent sentences, no? And yet they are not. Any abbreviation must have all it's points regardless of where in a sentence it stands. So, in fact, the second sentence is missing a period. This is plain to see here and on page 68 of your May, 2 issue.
You may, of course, edit your magazine in any way you wish, but you will still be wrong if you continue to do this."

Of course, 'cooperation' doesn't have an umlaut either, but one battle at a time.