Message

Information on cash discounts for prompt payment (Skonto) shall be provided within the element "Payment terms" BT-20 in the following way: First segment "SKONTO", second segment amount of days ("TAGE=N"), third segment percentage ("PROZENT=N"). Percentage must be separated by dot with two decimal places. In case the base value of the invoiced amount is not provided in BT-115 but as a partial amount, the base value shall be provided as fourth segment "BASISBETRAG=N" as semantic data type amount. Each entry shall start with a #, the segments must be separated by # and a row shall end with a #. A complete statement on cash discount for prompt payment shall end with a XML-conformant line break. All statements on cash discount for prompt payment shall be given in capital letters. Additional whitespaces (blanks, tabulators or line breaks) are not allowed. Other characters or texts than defined above are not allowed.

Context
(/ubl-invoice:Invoice | /ubl-creditnote:CreditNote)[$supplierCountryIsDE and $customerCountryIsDE]
Test
every $line in cac:PaymentTerms/cbc:Note[1]/tokenize(. , '(\r?\n)')[starts-with( normalize-space(.) , '#')] satisfies matches ( normalize-space ($line), $XR-SKONTO-REGEX) and matches( cac:PaymentTerms/cbc:Note[1]/tokenize(. , '#.+#')[last()], '^\s*\n' )
Usage
/ ubl:Invoice / cac:PaymentTerms / cbc:Note
/ ubl:CreditNote / cac:PaymentTerms / cbc:Note