Как правильно прочитать документацию (синопсис) bash команд?

man man

.

   Conventional  section  names  include  NAME, SYNOPSIS, CONFIGURATION, DESCRIPTION, OPTIONS, EXIT STATUS, RETURN VALUE, ERRORS, ENVIRONMENT, FILES, VERSIONS,
   CONFORMING TO, NOTES, BUGS, EXAMPLE, AUTHORS, and SEE ALSO.

   The following conventions apply to the SYNOPSIS section and can be used as a guide in other sections.

   bold text          type exactly as shown.
   italic text        replace with appropriate argument.
   [-abc]             any or all arguments within [ ] are optional.
   -a|-b              options delimited by | cannot be used together.
   argument ...       argument is repeatable.
   [expression] ...   entire expression within [ ] is repeatable.

   Exact rendering may vary depending on the output device.  For instance, man will usually not be able to render italics when running in a terminal, and  will
   typically use underlined or coloured text instead.