A "didgit" is the result of a stammering digit....
CT
Pretty sure that's not an AIX message. 'alphanumeric', 'uppercase' and
'lowercase' are all single words. That many errors in a single message
would likely never make it to the field. This is likely from an
installation-specific authentication method (a PAM, e.g.), making a
customer responsible for it.
Without more detail as to the AIX level involved, I can say that a
search in 5.3 and 6.1 revealed no messages (in tcbauth.cat) that bear
any resemblance to this text.