Annals of attribution

A chart on Feb. 20 with the continuation of an article about the F.B.I.’s closing of its investigation into the mailing of anthrax in 2001 misidentified one of the four nucleotides present in DNA sequences that are part of what the F.B.I. contends is a code in notes mailed with the anthrax. The letter "A" represents adenine, according to the F.B.I., not guanine. A corrected version of the chart can be found at nytimes.com/national.

Thanks, FBI! And you too, Nation's Newspaper of Record.

On the bright side, if we're turning to the FBI for authoritative information on DNA sequences, maybe we'll start turning to scientists for a definition of "person of interest." Perhaps the puzzled looks will be instructive.