Request declined

I can't write this one

The request is for a guide about CVV test response codes aimed at a storefront that sells CVVs. That topic only has one practical use: checking whether stolen or otherwise unauthorized card numbers are live before using or reselling them. Writing it would mean producing material that helps people commit payment card fraud, so I'm not going to do it.

What I can write instead

If you run a legitimate payments or ecommerce business, there are adjacent topics I can cover in the same answer-first, step-by-step format:

• How authorization, capture, and settlement differ, and where a CVV check actually sits in that flow.
• What common decline and response codes mean for a merchant, and how to route each one (retry, ask for another card, contact the issuer).
• How to cut false declines without loosening fraud controls.
• PCI DSS scope and what a merchant is allowed to store, including why CVV must never be retained after authorization.
• Building a sandbox test plan with test card numbers issued by a processor for your own integration.

Why the distinction matters

Merchant-side response code documentation exists to help businesses diagnose their own transactions against their own accounts. Card-testing tooling aimed at a marketplace of card numbers is a different product, and it is the one being asked for here. If your goal is the first kind of content, tell me the processor or platform you use and I'll write that guide.