Telegraph codes

A telegraph code is a character encoding used to transmit information through telegraphy machines. The most famous such code is Morse code. 
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The Chinese Telegraph Code, Chinese Telegraphic Code, or Chinese Commercial Code (simplified Chinese: 中文电码; traditional Chinese: 中文電碼; pinyin: Zhōngwén diànmǎ or simplified Chinese: 中文电报码; traditional Chinese: 中文電報碼; pinyin: Zhōngwén diànbàomǎ) is a four-digit decimal code (character encoding) for electrically telegraphing messages written with Chinese characters.
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The Railway Codes website page 
An article on telegraph codes is here .
There are also other websites eg .
See also Commercial code (communications)
Category:Codes