To provide end-to-end straight-through processing (STP) for SEPA-clearing, the EPC committed to delivering technical validation subsets of ISO 20022. Whereas bank-to-bank messages (pacs) are mandatory for use, customer-to-bank payment initialization (PAIN) message types are not; however, they are strongly recommended. Because there is room for interpretation, it is expected that several PAIN specifications will be published in SEPA countries.