in addition to the paper referred to by Art,
In the old SAS environment that used to be called SAS Display Manager, there is a command called COMMAND for which SAS On-line Documentation provides this
COMMAND <<WINDOW <"title"> | BAR
specifies the maximum number of commands to "remember" in the command bar drop- down list. Valid values are 0 through 50.
You must specify the WINDOW or BAR argument in the command before specifying the MAX argument.
So if your max is set below 50, then COMMAND bar max=50 will make a difference.