-N: help
-D: Display command list or help for given command.
-U: help [command]
-H: This command acts differently depending on whether it is executed in command
-H: mode or in insert mode. In command mode, the list of keybindings is printed.
-H: In insert mode, if no command is given, the list of commands is shown.
-H: Otherwise, the help for the given command is printed.
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-N: next
-D: Load next file.
-U: next
-H: Closes the current file and loads the next file of the playlist.
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