I was perusing MasterCard’s merchant support site, located here: MasterCard Merchant Rules. There are a number of documents linked from that site, including “MasterCard Rules”, which is 326 pages long. That document opens with “MasterCard Standards” which reads:

MasterCard is dedicated to making payments safe, simple and smart. We have a set of standards (“the Standards”) in support of this mission that provides our
Customers with clear direction as to their responsibilities. The Standards include the information contained in this MasterCard Rules manual and other manuals, along with guides, bulletins and policies that may be updated from time to time.

MasterCard’s “Chargeback Guide”, linked from the same site and one of the guides referenced in that paragraph, is 591 pages long. The “Transaction Processing Rules” is 302 pages long. The “Security Rules and Procedures” is 144 pages long.  There are a number of additional lengthy documents linked from the site.

Assuming that a merchant can wade through the thousand-plus pages of documentation and achieve some level of mastery of MasterCard’s rules, they should also be aware that those posted rules may not be up to date. From MasterCard’s merchant site:

You should also be aware that MasterCard rules and other standards change frequently. While we always strive to keep the documents on this Web site up to date, it’s possible that they will not always be absolutely current in all regards. In the event of any discrepancy between the documents found at this Web site and those rules and standards MasterCard deems to be the official rules and standards, the official rules and standards will apply.

The documentation on the MasterCard merchant site and the caveat that the documented rules may not represent official rules and standards does not strike me as “simple and smart”. There is a layup opportunity to make the merchant guidelines more user friendly and easier to comprehend.