Single-digit: self explanatory.
Purchase APR: Annual Percentage Rate, i.e., the interest charged periodically on balances in the Purchases category of an unsecured credit line such as a credit card.
It's on the Truth-in-Lending Act disclosure that must be provided by creditors to consumers who apply for and maintain credit accounts.
Makes no difference, anyone that doesn’t pay their credit card bill 100% every month on time should have their card revoked.