- The Tap Code was used by Vietnam prisoners to communicate, usually by tapping on metal bars or walls. It is a combination of Morse code and the Grid code replacing 'K' with a 'C' or 'X' , the dots (.) tell you what numbers to go to from top to side.
TAP CODE TABLE
1 2 3 4 5
1 A B C D E
2 F G H I J
3 L M N O P
4 Q R S T U
5 V W X Y Z
A(. .) B(. ..)
C(. ...) D(. ....)
E (. .....) F (.. .)
G(.. ..) H(.. ...)
I(.. ....) J(.. .....)
K(. ...) L(... .)
M(... ..) N(... ...)
O(... ....) P(... .....)
Q(.... .) R(.... ..)
S(.... ...) T(.... ....)
U(.... .....) V(..... .)
W(..... ..) X(..... ...)
Y(..... ....) Z(..... .....)
