There's a traditional, concise way of describing command syntax. Syntax
means the correct ways to combine various options and arguments. For
example, if you type man man to get the manual page about man, you'll see
several syntax descriptions beginning with the command name man. One of
them will look like this: man -k [-M path] keyword ...

Anything in brackets ([]) is an optional unit. In this case you don't have
to use the -M option, but if you do, you must use a path argument. You
must use the -k option and the keyword argument. The ... means that you
could have more of whatever came before it, so you could look up several
keywords.

Let's look at one of the more complex descriptions from the man manual
page:

man [-c|-w|-tZT device] [-adhu7V]

[-m system[,...]] [-L locale] [-p string]

[-M path] [-P pager] [-r prompt] [-S list]

[-e extension] [[section] page ...] ...

There's no need to go through all of this (and don't worry about what it
all means), but do pay attention to the organization of the description.

First, clusters of options usually mean you can use one or more of them in
different combinations, so -adhu7V means you can also use -h. However, you
can't always use all combinations; this description doesn't make that
clear. For example, -h is incompatible with other options, but you could