⁴²In protective relay circuit diagrams, it is conventional to show relay coils as “zig-zag” symbols rather than as actual coils of wire as is customary in electronic schematics. Those familiar with “ladder” style electrical wiring diagrams may recognize this as the symbol for a solenoid coil. Once again, we see here the context-dependence of symbols and diagram types: a component type may have multiple symbols depending on which type of diagram it’s represented in, while a common symbol may have different meanings in different diagrams.