| Symbol | Name | Meaning | Example |
|---|---|---|---|
[ ] | Square brackets | Optional | ls [-l] [FILE] |
< > | Angle brackets | Required placeholder | ssh <user>@<host> |
UPPER | Metavariable | Replace with real value | cp SOURCE DEST |
... | Ellipsis | Repeatable | FILE... |
{ | } | Braces + pipe | Choose exactly one | {start|stop} |
( ) | Parentheses | Grouping | (-c|-x|-t) |
-- | Double dash | End of options | rm -- -file |