You can do a DSPCMD on the Library/Command and see the program for validity checking. If you need to change it, you can do the CHGCMD on the Command. Some of mine I have set as *NONE.
Generally, you don’t assign validity checker programs to commands that you didn’t create. The parameters are not documented — some command parameters are hidden. There is no way to predict if the parameters will be the same after applying PTFs or release upgrades.
If you don’t want a user to have access to a command, don’t give authority to run the command.