Order date format attribute required

Error FX-SCH-A-000784 Factur-X

Attribute '@format' is required in this context.

Mandatory rule: As long as it is violated, the invoice is invalid and will be rejected by validators.
What is wrong

The qdt:DateTimeString in the order reference has no format attribute.

What the rule means

The format attribute identifies the format of the date value in the order reference.

Please add the date format to the order reference

The format attribute is missing from qdt:DateTimeString in the order reference. Add the format attribute to identify the date value.

What to do
  1. Add the format attribute to qdt:DateTimeString in the order reference.
  2. Regenerate the invoice and validate it again.
What it looks like
✗ Triggers the message 
<qdt:DateTimeString>...</qdt:DateTimeString>
✓ Correct 
<qdt:DateTimeString format="">...</qdt:DateTimeString>
Technical details

The test checks whether the format attribute is present on qdt:DateTimeString; this test does not validate its value.

Where the rule applies

The rule applies to qdt:DateTimeString within the date of the ultimate customer order reference.

Context (rule/@context)
/rsm:CrossIndustryInvoice/rsm:SupplyChainTradeTransaction/ram:ApplicableHeaderTradeAgreement/ ram:UltimateCustomerOrderReferencedDocument/ram:FormattedIssueDateTime/ qdt:DateTimeString
Test expression (assert/@test)
@format