Should my cat utility support multiple keys simultaneously?

So, i was given a task to implement simple version of cat utility. It should support some of GNU keys, for given text returns the same results as real cat utility and i was given this synopsis:

cat [OPTION] [FILE]...

What i want to know can my utility be called with multiple keys or just with one?

cat -b file

or

cat -b -s -e file

[POSIX](https://pubs.opengroup.org/onlinepubs/9699919799.2018edition/)(in BaseDefinions, chapter 12) says: > The notation used for the **SYNOPSIS** sections **imposes requirements on the implementors of the standard utilities** and provides a simple reference for the application developer or system user. And it the same chapter [POSIX](https://pubs.opengroup.org/onlinepubs/9699919799.2018edition/) says: > Ellipses ( "..." ) are used to denote that **one or more** occurrences of an operand **are allowed**. --- So if **OPTION** can be repeated, why there is no ellipsis after it in synopsis? For example, there is an ellipsis [man7.org](https://man7.org/linux/man-pages/man1/cat.1.html) :

-plaintext
cat [OPTION]... [FILE]...

but not [gnu.org](https://www.gnu.org/software/coreutils/manual/html_node/cat-invocation.html)( but this cat allows many options):

-plaintext
cat [option] [file]...

Can someone explain should my program work with many keys at a time and why? And why [gnu.org](https://www.gnu.org/software/coreutils/manual/html_node/cat-invocation.html) doesn't follow this(ellipsis) utility syntax convetion?