# PEPPOL-T19-R018

Source: https://xmlvalid.com/rules/PEPPOL-T19-R018

> Specification identifier SHALL start with the value 'urn:fdc:peppol.eu:poacc:trns:catalogue:3'.

- Level: error
- Rule sets: Peppol Catalogue rules 3.5
- Context: `cbc:CustomizationID`
- Test: `starts-with(normalize-space(.), 'urn:fdc:peppol.eu:poacc:trns:catalogue:3')`

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