SCOR (or "ISO Creditor Reference", "ISO 11649 RF reference") is an alphanumeric structured reference up to 25 characters long, prefixed by "RF" + two mod-97 check digits. Where QRR is Swiss-only and numeric, SCOR is cross-border and alphanumeric — usable in any SEPA SCT or cross-border CBPR+ flow that supports structured remittance.
The reference is carried in pain.001 inside <RmtInf>/<Strd>/<CdtrRefInf>/<Ref>. On the inbound camt.053 side it is echoed back inside <TxDtls>/<RmtInf>/<Strd>/<CdtrRefInf>/<Ref> — the StrdCdtrRef carrier in iso-compliant's KeyCarrier union.
A SCOR reference is the recommended way to embed a structured invoice id in a SEPA payment. The mod-97 check (computed over the alphanumeric, after converting letters A=10..Z=35) guarantees the reference cannot be silently corrupted in transit. iso-compliant validates SCOR check digits at parse time so a malformed inbound carrier is flagged as a low-confidence candidate.