This web content discusses the Enigma M4 message, P1030680, which is being decrypted by the Enigma@Home project. The message consists of a ciphertext and preliminary interpretation, but the plaintext and final interpretation remain unknown. Dan Girard’s analysis of the message revealed that the operator made a mistake and did not check the Zuteilungsliste. He assumed that the Schlüsselkenngruppe “ACH” was assigned to Potsdam, and he was unsuccessful in deciphering the message. The Grund settings used by the German Navy no longer exist, so a software program can determine the settings needed to produce a particular message key.
https://enigma.hoerenberg.com/index.php?cat=Unbroken&page=P1030680