Final answer:
The set of rules issued by the PCI Council is a Compliance standard that merchants must follow if they choose to accept payment via credit card.
Step-by-step explanation:
The set of rules issued by the Payment Card Industry (PCI) Council, which merchants must follow if they choose to accept payment via credit card, is a Compliance standard. This set of rules describes best practices for securing credit card processing technology, activities for securing credit card information, and how to protect customers' data. It is issued by the PCI Council, which is a committee made up of representatives from major credit card providers (Visa, Mastercard, American Express) in the United States.