internal static bool IsHeaderValue (string value)
{
// TEXT any 8 bit value except CTL's (0-31 and 127)
// but including \r\n space and \t
// after a newline at least one space or \t must follow
// certain header fields allow comments ()
int len = value.Length;
for (int i = 0; i < len; i++) {
char c = value [i];
if (c == 127)
return false;
if (c < 0x20 && (c != '\r' && c != '\n' && c != '\t'))
return false;
if (c == '\n' && ++i < len) {
c = value [i];
if (c != ' ' && c != '\t')
return false;
}
}
return true;
}