Just FYI:

Wal-Mart Coupon Policy

 Wal-Mart accepts the following types of coupons (see guidelines below):

    * Manufacturer coupons (Cents Off)
    * Free merchandise (or Buy-One-Get-One-Free) coupons
    * Store coupons
    * Pharmacy (Advertising and Promotional) coupons
    * Internet coupons
    * Soft drink container caps

The following are guidelines and limits:

    * Wal-Mart only accepts coupons for merchandise we sell and only when presented at the time of purchase.
    * Coupons should have an expiration date and be presented within the valid dates. Wal-Mart will not accept expired coupons.
    * Internet coupons should be legible and say "Manufacturer Coupon."  There should be a valid remit address for the manufacturer and a scannable bar code.
    * Only one coupon per item is permitted.
    * Use of 40 or more coupons per transaction will require approval by Customer Service Manager.


http://www.walmartfacts.com/search/default.aspx?srchtxt=coupon