A working paper or a discussion paper or something else?
JEL classifications are just that: classifications. Anyone can put such a classification on his paper, and it doesn't have anything to do with publishing in the JEL - it's more like a keyword.

To your question: I don't think there really is such a big difference between a working paper (which is work in progress, typically distributed to be discussed) and a discussion paper (which is work in progress, typically distributed to be discussed). All of these are essentially manuscripts under preparation for submission to a refereed journal (in CS, a conference). So I would file all of these under "non-reviewed papers".