BR-CL-24
For Mime code in attribute use MIMEMediaType.
What does this rule mean?
An attachment (BT-125) declares a MIME type EN 16931 does not permit.
Exactly six are allowed: PDF, PNG, JPEG, CSV, XLSX and ODS. Those are the ones a receiver can open without a prior agreement — anything else they would have to guess at or reject.
Official rule message (standard)
For Mime code in attribute use MIMEMediaType.
Where the rule applies
Syntax: CII · UBL
The same rule, expressed twice: UBL and CII name the same fields with different paths. Running a CII file against the UBL rules is why you get errors that mean nothing.
UBL
cbc:EmbeddedDocumentBinaryObject[@mimeCode]
CII
ram:AttachmentBinaryObject[@mimeCode]
Technical test
The rule passes when this Schematron expression holds true:
((@mimeCode = 'application/pdf' or @mimeCode = 'image/png' or @mimeCode = 'image/jpeg' or @mimeCode = 'text/csv' or @mimeCode = 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' or @mimeCode = 'application/vnd.oasis.opendocument.spreadsheet'))How to fix it
A wrong code-list value. A tool can suggest a valid code, but you confirm the correct one.
Convert the file to a permitted type (a Word document to PDF, say) and correct the mimeCode. Only an XRechnung Extension additionally allows application/xml, and only by prior agreement with the receiver.
Correct the affected entry in your XML, then re-check the invoice. Validation runs locally in your browser — your file never leaves your machine.
Check an e-invoice here
Drop an XML or ZUGFeRD PDF file here. Validation runs locally in your browser against EN 16931 — your file never leaves your machine.