Deciphering British diamonds on United States covers

U.S. Stamp Notes by John M. Hotchner

Some years ago, as I pursued United States auxiliary markings showing delays in the mail, I began to notice that U.S. mail addressed to England sometimes had a black or gray diamond marking on the front. See the Oct. 26, 1951, cover in Figure 1.

Once I had noticed, I also found foreign mail from countries other than the United States coming into England that also received the diamond marking, and I found the marking existed on British mail sent to the United States.

All of those markings were gray. But when I found a cover that had a red diamond, shown here in Figure 2, I decided it was time for an explanation.

So, I asked British expatriate Michael Dixon, a professional and philatelic colleague of mine. He readily knew exactly what I was talking about and provided the following explanation:

“Once a year, the General Post Office (now Royal Mail) conducted a census — a numerical count — of mail handled. This is purely a Post Office internal exercise (which showed how workload had increased or decreased). Usually they did this one week in August or September.

“To avoid a mail item being counted twice, the items counted initially are passed through cancelling machines where the date-stamp has been replaced with an open diamond in black or shades of grey. As the postal workers ran out of fingers, thumbs and toes, every one hundredth item counted was marked with a red diamond to make the tally easier for the workers.

“Covers with these marks are not scarce — even the red diamond ones — and are readily available, though most dealers don’t identify them as anything special.”

I have found a dozen or so incoming covers with the black or gray markings, one with the red diamond, and one on a cover with British postage coming into the United States.

The earliest example I have is from 1947; the latest one was canceled in the United States in October 1970. Most were mailed in the 1950s.

If you have an accumulation of British covers, it might be worth your while to check to see if you have any bearing these diamond markings, now that you know what to look for.

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