Guide to manual syntax?

Is there a page that explains the syntax used in PHP.net explanations and function signatures? For example: array *array_chunk* ( array $input , int $size [, bool $preserve_keys = false ] ) It is my understanding that the above method returns an array, the $input is an array, $size is an int and it has some optional params denoted by the [ ]. I figured this out through looking at some methods I knew and reading lots of methods on the site but is there a reference to this syntax somewhere? I think it would be very helpful to new people trying to read the references on the site.