Single keys can be made to execute commands when the cursor is at the
beginning of a headline, i.e., before the first star. Configure the variable
org-use-speed-commands to activate this feature. There is a
pre-defined list of commands, and you can add more such commands using the
org-speed-commands-user. Speed keys do not only speed up
navigation and other commands, but they also provide an alternative way to
execute commands bound to keys that are not or not easily available on a TTY,
or on a small mobile device with a limited keyboard.
To see which commands are available, activate the feature and press ? with the cursor at the beginning of a headline.