Two terminals may collate their transcriptions. The node reports only the count.
One terminal requests a code and reads it to the other. The other presents the code. The node compares the two transcriptions and reports the number of discrepancies, nothing else. Codes hold for fifteen minutes and are honored once.
the desk is reading this terminal.
the desk compares transcription states only. it does not name the record, the sentence, or either reading, and it keeps no ledger of results.