[quote Mike Johnson]I was taught not to place my hand over my heart, that being reserved for the pledge. It was taught that way both in school and in Cub Scouts. Until recently, I was bothered when I saw people putting their hands over their hearts during the Anthem.
"(b) Conduct During Playing. - During a rendition of the national
anthem -
(1) when the flag is displayed -
(A) all present except those in uniform should stand at
attention facing the flag with the right hand over the heart;
(B ) men not in uniform should remove their headdress with
their right hand and hold the headdress at the left shoulder,
the hand being over the heart; and
© individuals in uniform should give the military salute at
the first note of the anthem and maintain that position until
the last note; and
(2) when the flag is not displayed, all present should face
toward the music and act in the same manner they would if the
flag were displayed."
Well, this has been on the books at least since July 7, 1976, or as early as June 22, 1942 (I'm too lazy to look up the sources referenced):
http://uscode.house.gov/download/pls/36C3.txt