Complex sentence: Many early Netherlandish masters have not been identified, and are today known by "names of convenience"; the practice lacks an established descriptor in English, but the "notname" term is often used, a derivative of a German term.
Split into simpler sentences: Many early Netherlandish masters have not been identified, and are today known by "names of convenience". The practice lacks an established descriptor in English, but the "notname" term is often used, a derivative of a German term.