# ibr-064

Source: https://xmlvalid.com/rules/ibr-064

> The Item standard identifier (ibt-157) MUST have a Scheme identifier.

- Level: error
- Rule sets: PINT Billing rules 1.1.3, PINT Billing rules (as shipped with PINT AE) 1.0.4
- Context: `cac:InvoiceLine/cac:Item/cac:StandardItemIdentification/cbc:ID | cac:CreditNoteLine/cac:Item/cac:StandardItemIdentification/cbc:ID`
- Test: `exists(@schemeID)`

Validate a document against these rules: https://xmlvalid.com/validate