As many have stated you are limited to 8 upper case characters, 7 if you still use UADS; however if the MQ user is off-platform, perhaps one of the various tools for mapping other IDs to a RACF ID could be used? These are all part of RACF (not sure about ACF2 or Top Secret) but as I see it they boil down to authenticating using some non-RACF method, then taking that ID and mapping it to a RACF ID, which would be the ID used in the ACEE (and probably other places), but the user wouldn't necessarily need to know it.
There are probably people on this list far more expert in those than I am, having never had to implement one of them, but I know they exist. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN