Ok, would be more understandable if response in computer was 'NOT stocked' or 'no product sku# found in this store'. 'OUT OF STOCK' usually infers to: 'stock was for sale but sold out'.
Thanks PW, to add some further details from my use of CVS Brickseek:
When you do a search it only cheks a certain number of stores that are near the zip code you provide.
If it is a dense urban area with a lot of CVS stores it may only be a 5 mile radius. With 9800 CVS Stores in the US and 42,000 zip codes there is no way we have checked every store.
In addition to the Green "Qty on Hand" response and the Red "Out of Stock" there is a Light Green "Low Stock" response. This may be CVS way to identify stores that normaly stock a product but are currently low or out of stock, just a guess by me.