People now use the term “parlor” in a lot of different ways. “0” sized guitars are small but I don’t consider them parlor guitars.
Here’s what Pono includes in their Parlor Series: https://www.ponoukulele.com/new-page-1
They are about an inch narrower, and are also quite a bit less expensive. Pono was selling the all-mahogany L20 (which I prefer to Acacia) for $500 brand new just a few months ago. They are now out of stock.