Familygram

A familygram is a personal message sent by their families to sailors of the United States Navy or the Royal Navy serving in submarines.

Because submarines normally maintain radio silence to avoid detection, personal messages from the 'outside world' are severely restricted. Familygrams were originally limited to 15 words, though later as many as 50 words were permitted. Content was also severely restricted. Familygrams were not private communications. Familygrams were scanned for content before being transmitted, and scanned again before delivery to the intended recipients. There are many examples of such familygrams on the Internet, dating from the Vietnam War and earlier.