DNS Update Message Pre-req TYPE value 0xFF

[Jeff Stevens]

I've been studying a raw data transaction that I don't quite understand
yet after inspecting RFC 2136 (DNS Update) and
http://www.iana.org/assignments/dns-parameters

It appears the pre-req section specifies a TYPE of 0xFF (255 dec) which
is supposed to be "ALL" per dns-parameters but the bind trace appears to
view it as "ANY".  The dns-parameters doc confuses the issue a little by
using the literal description of "*". The only thing that makes sense
here is to consider 0xFF means "ANY" even though dns-parameters seems to
imply ANY is not a valid TYPE.

Is someone able to clarify this for me?  Thanks!
-- 
Jeffrey Stevens