The following typographical conventions are used in this manual:
/etc/passwd: filenames and directory names
placeholder: replace placeholder with the actual value
PATH: the environment variable PATH
ls, --help: commands, options, and parameters
user: users or groups
Alt, Alt+F1: a key to press or a key combination; keys are shown in uppercase as on a keyboard
, : menu items, buttons
Dancing Penguins (Chapter Penguins, ↑Another Manual): This is a reference to a chapter in another manual.