Which commands should I use when creating keyboard shortcuts for shutdown and reboot in Loki?
Based upon the lack of description in the original question I am going to take a shot in the dark in believing you're asking how to create keyboard shortcuts for shutdown and reboot.
If this is the case, you can open System Settings->Keyboard. Then click on Shortcuts, then Custom. Here you can enter the command you wish to run then create a two key accelerator. For instance in command, I typed
reboot then clicked on 'New accelerator' and held the Super Key and the letter 'R' which created a shortcut to reboot by holding my Super Key and hit 'R'.
Again, not sure if this was what you're looking for but this is how you create custom keyboard shortcuts.