Webster:
code... a system in which arbitrary values are given to letters, words, numbers or symbols to ensure secrecy or brevity...

There can be many more reasons of course, like representation on a medium different than a standard printed medium (and in that case we can not even speak about values given to something), or ability for mechanical reading and writing (and also in that case the wording is quite wrong).

The intent of this set of pages is to show the codes I have encountered in the course of time. As most of this is based on observation and an enormous amount of (often conflicting) sources it is of course laughably incomplete and will certainly contain numerous errors. I do however welcome all additional information and corrections. Also other codes are very welcome. It is however not my intention to give cryptographic information (i.e. the secrecy part in Webster's definition) here. Please e-mail to me.

For the time being two kinds of visual codes are shown here:

• barcodes
• character recognition codes

• punched papertape, card and tags
• magnetic tape
• internal codes
• standards on codes

• International Standard Book Numbers
• International Standard Music Numbers
• International Standard Serial Numbers

Also now the Morse, Braille and Maritime Flag codes are available:

• Morse Code
• Braille Code
• Maritime Flag Code