# PEPPOL-T16-B20401

Source: https://xmlvalid.com/rules/PEPPOL-T16-B20401

> Attribute 'schemeID' MUST be present.

- Level: error
- Rule sets: Peppol Despatch Advice rules 3.5
- Context: `/ubl:DespatchAdvice/cac:DespatchLine/cac:Item/cac:StandardItemIdentification/cbc:ID`
- Test: `@schemeID`

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