charsetSentinel property

Some services add an initial utf8=✓ value to forms so that old InternetExplorer versions are more likely to submit the form as utf8. Additionally, the server can check the value against wrong encodings of the checkmark character and detect that a query string or application/x-www-form-urlencoded body was not sent as utf8, eg. if the form had an accept-charset parameter or the containing page had a different character set.

QS supports this mechanism via the charsetSentinel option. If specified, the utf8 parameter will be omitted from the returned Map. It will be used to switch to latin1/utf8 mode depending on how the checkmark is encoded.

Important: When you specify both the charset option and the charsetSentinel option, the charset will be overridden when the request contains a utf8 parameter from which the actual charset can be deduced. In that sense the charset will behave as the default charset rather than the authoritative charset.