Command
    What mpv command to run,
    see 
MPV Commands
    for a list of available commands.
    Not all commands will work as some are specific for mpv.
    Most useful are the commands to manipulate properties,
    like 
set, 
add, 
cycle.
    
set: sets the value of a property 
set volume-max 150.
    
add: increases/decreases the value of a property 
add volume 15,
    increases volume by 15. To decrease the value use 
add volume -15.
    
cycle: cycle through the values of a property 
cycle aid up.
OSD message
    An OSD message to display when triggering an action type custom command.
    Use ${property_name} to display the value of a property Volume: ${volume}.
Keyboard shortcut
    The command will be triggered with a shortcut. The shortcut can be set after saving.
Run at startup
    The command will be run at application startup.
    Startup commands can be toggled, meaning you can choose whether they are set on startup or not,
    this is available after saving.