A check digit is required with check digit algorithm 1 (the standard EAN check digit algorithm). In the case of internal number assignment, the check digit is determined automatically.
A check digit is not required with the other check digit algorithms. They identify the format of the EAN, for example, 3 indicates a fresh produce EAN with a Standard Article Number (SAN).
If you specify an EAN, but not an EAN category, when creating an article master record, the system determines the EAN category automatically. If you specify the EAN category, but not an EAN, the system determines the EAN automatically if internal number assignment is allowed by the EAN category.