Tap code

**Latin alphabet tap code table**
	1	2	3	4	5
1	A	B	C/K	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

The tap code, sometimes called the knock code, is a way to encode text messages on a letter-by-letter basis in a very simple way. The message is transmitted using a series of tap sounds, hence its name.^[1]

The tap code has been commonly used by prisoners to communicate with each other. The method of communicating is usually by tapping either the metal bars, pipes or the walls inside a cell.

^ The Handbook Of The SAS And Elite Forces. How The Professionals Fight And Win. Edited by Jon E. Lewis. p.199-Tactics And Techniques, Evasion, Capture And Escape. Robinson Publishing Ltd 1997. ISBN 1-85487-675-9

[1] The Handbook Of The SAS And Elite Forces. How The Professionals Fight And Win. Edited by Jon E. Lewis. p.199-Tactics And Techniques, Evasion, Capture And Escape. Robinson Publishing Ltd 1997. ISBN 1-85487-675-9

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