The standard isn't just a list of shapes; it follows a strict grid-based system for precision in Manuals of Engineering Drawing :
: Clear representations for terminals, plugs, sockets, and cable fittings. DIN EN 60617 3 1997 08 pdf
: Symbols are designed on a modular grid (often using a module "M") to ensure they fit perfectly into computer-aided drafting (CAD) systems. The standard isn't just a list of shapes;
: Standard symbols for single lines, groups of connections (such as 3-phase circuits), and specialized items like screened or twisted conductors. DIN EN 60617 3 1997 08 pdf