ONE_SHOT is a type of authentication used for a print job (only). The print job itself contains the authentication information like user code and is used by the MFP to authenticate the user when job comes in. The job is automatically authenticated by the MFP and not a user. The ONE_SHOT does not require a user's login information from the panel. The job is automatically authenticated by the MFP and then logs out automatically. It goes through without having any manual intervention. The ONE_SHOT login always requires a user code in the job file when the following settings are set: [Enhanced External Charge Unit Management] ->[Printer] is selected. Typically the code is added by a print driver. NORMAL_MODULE is another type of auth, meaning initiated by the panel and in your application you set the 8 digit code.