RFC 1521:MIME (Multipurpose Internet Mail Extensio...
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charset parameter


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... The charset parameter ...
... Unlike some other parameter values, the values of the charset parameter are NOT case sensitive. The default character set, which must be assumed in the absence of a charset parameter ...
... charset parameter are NOT case sensitive. The default character set, which must be assumed in the absence of a charset parameter, is US-ASCII. ...
... definitions. This RFC specifies the definition of the charset parameter for the purposes of MIME to be a unique mapping of a byte stream ...



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