BR-KSA-29

If the cryptographic stamp (KSA-15) exists in the invoice, this cryptographic stamp (KSA-15) must contain the exact "urn:oasis:names:specification:ubl:signature:Invoice" value for referenced signature ID and signature ID.

warning: reported, still valid

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.

Context
cac:AdditionalDocumentReference/cac:Attachment
Test
exists(cbc:EmbeddedDocumentBinaryObject) and (cbc:EmbeddedDocumentBinaryObject) != '' and (//cac:Signature/cbc:ID) = 'urn:oasis:names:specification:ubl:signature:Invoice'

Checked with Saudi Arabia ZATCA Tax Invoice (UBL), Saudi Arabia ZATCA Simplified Tax Invoice (UBL)