ery rare case in which a standard OTP response could
   be a valid coding in both the hexadecimal and six-word formats. An
   example of this is the response "ABE ACE ADA ADD BAD A."  The
   solution to this problem mandated by the OTP specification is that
   compliant servers MUST attempt to parse and verify a standard
   response in both hexadecimal and six-word formats and must consider
   the authentication successful if either succeeds.

   This problem can be solved easily using extended responses. T