F-LIB157

PaymentMeansCode = 93, InstructionID must be equal to 16 characters (when PaymentID equals 75)

error: the document is invalid

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.

Test
(cbc:PaymentMeansCode = '93') and cbc:PaymentID = '75' and string-length(cbc:InstructionID) != 16

Checked with Denmark OIOUBL 2.1 Invoice