Punicode: Upper-case in example

In http://www.ietf.org/internet-drafts/draft-ietf-idn-punycode-03.txt,
example (I) says:

  (I) Russian (Cyrillic):
         U+043F u+043E u+0447 u+0435 u+043C u+0443 u+0436 u+0435 u+043E
         u+043D u+0438 u+043D u+0435 u+0433 u+043E u+0432 u+043E u+0440
         u+044F u+0442 u+043F u+043E u+0440 u+0443 u+0441 u+0441 u+043A
         u+0438
         Punycode: b1abfaaepdrnnbgefbaDotcwatmq2g4l

The presence of the upper-case 'D' (not to say the string 'Dot' :-)
is confusing, because it seems completely arbitrary. There is no
upper-case letter in the Cyrillic string.

Is the result string actually correct? Has it been generated mechanically?
How did the upper-case D get in there?

Regards,    Martin.