UTF 7 does map a sequence of code points to a sequence of bytes like the other UTFs but unlike them there is more than one valid way to represent a peice of text in UTF 7 and its output is designed to be used directly in internet mail Essentially it was a case of recognising that UTF 8 quoted printable insanely inefficiant encoding and doing it better by designing a single process for the entire task From a registration and mail header point of view UTF 7 is considered to be a character set e g its listed at