This is a great, straight-forward explanation of the Merchant Levels associated with PCI DSS.  Thanks to the team at Tripwire for sharing.  Everyone should have this information internalized or readily available for discussion when supporting customers or internal resources that process branded credit/debit cards.

https://www.tripwire.com/state-of-security/regulatory-compliance/pci/pci-dss-merchant-levels-penetration/