Guides
TRL — transmission trailer
The last line of the file states how many groups, transactions, and physical records the file contains. If these totals don't match reality, receivers treat the file as truncated or edited.
The exact field layout — positions, sizes, and formats — is defined in CISAC's CWR specification (CWR19-1070R1), available to CISAC members and licensees. The validator implements the full layout: drop a file on it and every TRL line is parsed field by field, with problems tied to the exact characters at fault.
Check a CWR file free — errors and warnings tied to the exact line, nothing stored: cwrcheck.com.