AcceptCharSet is a String property that indicates the character sets accepted in a resulting HTTP response. AcceptCharSet may contain any valid Character set value as described in the Internet Standards document: 

RFC 1700, Assigned Numbers  

Each charset value may have an associated quality value which represents the user's preference for that charset. The default value is q=1. For example: 

  iso-8859-5, unicode-1-1; q=0.8

The special value "*" in Accept-CharSet matches every character set including ISO-8859-1. If no "*" is present in AcceptCharSet, then all character sets not explicitly mentioned get a quality value of 0, except for ISO-8859-1, which gets a quality value of 1 if not explicitly mentioned. 

If no AcceptCharSet header is present, the default is set to allow any character set.