What is a non-diminishing (non-stock) product?
A non-diminishing product, also known as a non-stock product, is an item that does not reduce inventory levels when added to a sales order or quote.
These are most commonly used for services, digital goods, or special items that aren't tracked in stock inventory.
To set a product as non-diminishing / non-stock when creating a new product, tick the Non-diminishing option on the list product entry page.