Peppol SMPs (publishing the capabilities of Peppol participants)
To deliver electronic documents from a sender to the correct recipient, all Peppol access points need to know about each other. To do this Peppol maintains one centralized service, called the Service Metadata Locator (SML). The Peppol SML defines which Service Metadata Publisher (SMP) to use for finding out the delivery details of any Peppol participant.