ISO 18245 is an ISO standard concerning the assignment of merchant category codes (MCC) in retail financial services.
These are used to control usage of corporate credit cards.
MCCs are assigned by merchant type (e.g. one for hotels, one for office supply stores, etc.
For example, MCC 5967 represents "Inbound telemarketing merchants."
They are generally reserved for merchant categories having at least $10 million annual revenue.