I would love to have the ability to hide a Libref or Fileref in DMS Explorer (or elsewhere). If I fx have a concatinated libref contaning 3 librefs I can see all 4. It could be a simple option on the libname statement; hide=yes or visible=no (or something else). I agree that this would be in effect for all users if you use a common autoexec, but you can overwrite this by including a personal autoexec allocating the same libref without the "HIDE"-option.
The hidden libref should of course be available for use.