DISC means there is a Discrepancy with your advancement information and your Final Multiple Score cannot be calculated until this error is corrected through your ESO and the Navy Advancement Center (NAC) with supporting documentation. An uncleared discrepancy can keep an otherwise qualified Sailor from being advanced.
The most common discrepancies are:
Performance Mark Error - this means that your Performance Mark Average is missing from your exam answer sheet or is out of range. This is the number one discrepancy.
Insufficient Time-in-Rate - this means that your time-in-rate (TIR) is less than the required needed for the next paygrade or you have not been identified properly for Early Promote TIR waiver.
Unmatched Name/SSN - this means that your Name/SSN translated from the DOD ID Number does not match the Enlisted Master File (EMF) created from the Navy Enlisted System (NES) or the Inactive Manpower and Personnel Management Information System (IMAPMIS).
Wrong Path of Advancement - this means that you participated in an Navy-wide advancement examination outside your normal path of advancement.. (i.e. - a BM3 took a MA2 exam)