SI-UBL-2
Document should not contain empty elements.
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
//*[not(*) and not(normalize-space())]
Test
false()
Checked with Netherlands SI-UBL 2.0 Invoice (NLCIUS), Netherlands SI-UBL 2.0 Credit Note (NLCIUS)