CHARMAP parameter*  ==  CHARMAP=mapType:charMap[,charMap]*[:tosv]
           mapType  ==  ascii | ucs | jis | ucsjis | jisucs
           charMap  ==  inCharCode1[-inCharCode2]/outCharCode2[-[outCharCode2]]
          charCode  ==  hexa-decimal code | single ASCII character
                    --  default: none

If specified, a character in texts relayed in a message of an application protocol is mapped to another character. By default, the mapping is applied to the response data to client. It can be applied to the request data to server specifying ":tosv".

A character to be mapped is represented in a hexa-decimal value of it (represented in more than 2 columns), or a direct character in a single columns. The characters in the JIS X 0208 character set encoded in the variants of its encoding (ISO-2022-JP, EUC-JP, and Shift_JIS) are represented in its JIS code value without the most significant bits (8080) as "2121". The characters in the JIS X 0212 character set are represented in its JIS code value prefixed with "1" as "1222F".
If inCharCode2 and outCharCode2 is specified, each character in the range is mapped to the corresponding character. If no -outCharCode2 is given, any input characters in the range is mapped to outCharCode1.

The mapType is one of followings:

ascii -- ASCII to ASCII mapping

ucs -- UCS to UCS mapping when the input is coded in UTF-8

jis -- JIS to JIS mapping when the character set of input is JIS X 0208

ucsjis -- UCS to JIS mapping in the conversion by CHARCODE=JIS or SJIS or EUC

jisucs -- JIS to UCS mapping in the conversion by CHARCODE=UTF8

Example: reverse lowercase and upper case

CHARMAP=ascii:a-z/A-Z,A-Z/a-z


Example: "rot13" encoding

CHARMAP=ascii:a-m/n-z,n-z/a-m,A-M/N-Z,N-Z/A-M


Example: replace any Japanese character in JIS X 0208 with "GETA MARK"

CHARMAP=jis:0100-7F7F/222E


Example: replace any Japanese character in JIS X 0212 with "GETA MARK"

CHARMAP=jis:10000-1FFFF/222E


Example: represents unknown characters by "WHITE SQUARE" instead of "GETA MARK"

CHARMAP=jis:0000/2222