Use of

[parkov]

According to a website:

In the Marine Corps, the use of the word “repeat” on the radio is strictly forbidden. It is considered an offense of such magnitude it never occurs. The term used would be: “say again your last” or “I say again.”

Why is it such an unspeakable offense?

[dylan_73]

Repeated thread. Answered in http://boards.straightdope.com/sdmb/showthread.php?threadid=77917