syntax terminology

Question

Does anyone know the term for this form of command-line syntax notation? For instance, when specifying command-line arguments:

key[,alignment][:format]

So that key is a required argument, and can be followed by a space and an alignment parameter, which can also be followed by a colon and a format.

It's not BNF. Is there a name for this?

Answer 1

Command line argument from Wikipedia lists a couple of terms for the switch, options or flags syntax depending on what operating system and program you are using.

Answer 2

I think you mean C-command