What the rule checks
As the rule set's publisher wrote it. The rule runs on every element the context matches, and fails where the test is false; the validator reports the line of that element.
EN 16931 rules (UBL) 1.3.17
EN 16931 rules 1.3.16 (UBL) 1.3.16
EXTENDED-CTC-FR rules (UBL) 1.4.0.04
Romanian RO e-Factura rules (UBL) 1.0.9
Context
/ubl:Invoice | /cn:CreditNote
Test
not(//@uri)
Checked with EN 16931 Invoice (UBL), EN 16931 Credit Note (UBL), Croatia eRačun Invoice (UBL), Croatia eRačun Credit Note (UBL)