It includes specifications for surface profiles, angular dimensions, and tool offsets (parting lines). OKW Gehäusesysteme Reference Documents & Tables

If your general tolerance block references "ISO 20457 – m", you do not need to write individual tolerances on every dimension. The machinist knows to adhere to the Medium tolerance table.

ISO 20457 (and its German equivalent DIN 16742) is the definitive global standard for manufacturing tolerances and acceptance conditions of plastic molded parts