If you spend long enough on eBay, eventually you'll run across the term "OOAK". This is an abbreviation meaning "one of a kind" or an original item. However, OOAK means different things to different people and is sometimes misleading if you don't understand the sellers meaning of the term. There are a few ways OOAK is used:
The first is a completely original one of a kind item that will never be produced again, in any form by that seller or the original creator. This is the purist form of the meaning of OOAK and what some folks expect. This can include something like a piece of art that will never be duplicated in any way, in any form. Nothing like it will be made again by that artist or craftsman. It is truly an original piece.
The second form of OOAK is often used in pieces that are hand made in some way. More pieces of its kind may be produced, sometimes in large numbers, but since each piece is made by hand it can be considered "original", even though many of them may be made over time. As a woodworking shop, it is often tempting for us to use the term, as each piece we create has unique grain, is handmade, and no two are exactly alike. Although we try to refrain from using the term in this way, in this sense it may be justified as OOAK.
In another sense OOAK can mean that the "design" of the item is unique. This perhaps can be the most questionable form of OOAK depending on the piece. For instance, in making our miniature doors, if it is modeled after a real-life Tudor or raised panel style door commonly found in architecture, is the design truly OOAK? Rather more to the point might be that the design is original in miniature scale. There is also the fact that the uniqueness of the item in question is based on the knowledge of the seller. Especially in handmade goods ... out of tens of thousands of craftsmen and women and over many years, the item may or may not have been done before. In our case, we believe our handmade wee folk doors and miniatures to be original and unique and have been creating them on and off since the mid 1970's. But even our product was originally inspired by a previous fantasy work and built upon until they were unique products in their own right. And more recently we have folks that have blatantly copied our work and called it OOAK!
So when you see the term, take it with a grain of salt and in the spirit that the seller means it. If in doubt, contact the seller and ask their meaning of OOAK. Is it OOAK because each one is made by hand? Will it ever be reproduced? Are other items very similar to it produced on a regular basis? Many uses of OOAK are valid, just be aware of the context for the item in question.