http://www.amazon.com/gp/help/customer/display.html?nodeId=1161312#il_required
The data you enter for these desired fields gives customers the basic information they need to make an informed purchasing decision. We highly recommend that you fill in all desired fields. Not providing data in desired fields can result in poor product descriptions and make your product hard to find. If a product exists on Amazon.com but does not have a price or quantity, customers cannot buy it.
Each product sold on Amazon.com also includes an industry standard product identifier. This field is required for product matching when creating new listings.
The following are recognized by Amazon as product IDs:
The product-id-type is a numerical entry that indicates if the product-id is an ASIN, ISBN, UPC, or EAN. This is a required field if product-id is provided. The options include:
This is a numeric entry that indicates the condition of the item. This field is required for creating a new listing.
Condition types:
The price per item, in U.S. dollars. Do not include the "$" symbol. The price has to be greater than zero (0.00). This is a required field if product-id is provided and you are creating new listings. You must provide a price to make the item available for purchase on Amazon.com.
You must enter a quantity when adding a new SKU. You can set the quantity anywhere between 1 and 1,000. This is a required field for seller-fulfilled items if product-id is provided, and to make the item available for purchase on the website. Items must be in-stock and on-hand at the time a purchase is made.
Use this field to describe any differences your item has from the new item sold by Amazon.com (for example, if your hardcover book is missing the dust-jacket). This field is limited to 1,000 characters for all Used, New, Collectible, and Refurbished items.
A code that indicates the countries to which you are willing to ship:
If you do not enter an option, the general setting you chose when you signed up to sell will be used as the default.
If you do not enter the value "international" in the expedited-shipping column, only International Standard shipping will be available. You can offer International Standard, International Expedited, both, or neither.
By selecting to ship internationally, your item will appear on other Amazon sites when there are no offers from a marketplace seller. You are solely liable to comply with the laws and regulations of the country from which you are shipping your products and also for the country to which you are shipping, as applicable. The international buyer may have to pay customs duties, taxes and processing fees for your product.
Enter "n" if you will not offer expedited shipping at all for the item. Enter "y" if you will only offer Domestic Expedited, but not Domestic Two Day, Domestic One Day, or International Expedited.
These are the valid expedited-shipping values for BMVD Items:
If you offer more than one expedited shipping option for a BMVD item, don't use the "y" value; use only the words domestic, second, next, and international, in any combination. Use the words exactly as listed and separate them with commas. Here are some examples of valid entries for the expedited-shipping column: