“capacity / -ies” appears everywhere where capacitance is meant, and “grad” in the circuit diagrams should be taken to read: degree(s). Remarkably though, the word capacitor is correctly used throughout the book. Although a spell check of the text is unlikely to flag a large amount of mistakes, the correct electronics terms are often missing, and grammar compliance is weak. A simple sentence like this one:

... Diode D2 is designed for instantaneous  discharge of capacitor C2 when the “correct” code is dialed. ...

may be misinterpreted to mean that a special diode got designed for the circuit. More likely though, the word “in” or — lengthier — “into the circuit” is missing between “designed” and “for”, the diode being a dead common 1N4004 (!) as revealed by the referring schematic.

In another place I saw two diodes, three resistors and a capacitor described as a “chain of elements” when a “network” is probably meant. Here, a case of hyper formal language which is not wrong per se but really unwanted and possibly confusing as there is no such thing as a chain structure in that circuit.

All’s not well with the layout or pagination either. The index at the end if the book proved erratic on three of ten terms I was trying to find information on.

That said, once you are accustomed to, and aware of, the occasional oddity with the tech-language