Alright, so I found out after giving players the permission node "-bukkit.command.version" They cannot do that anymore
That might be true but a plugin can block commands so people who know the plugin can't do the command and the person who did the command knows the plugin they are using for Example: someone does the command /pex and the permissonEX prefix comes up they know what plugin you are using for groups with a plugin it will say unknown command