* Capacitor - general, style 2.
The distance between the plates shall be between one-fifth and one-third of the length of a plate.Capacitor - General, with an identified electrode. Style 2.If it is necessary to identify the capacitor electrodes, the curved element shall represent:--(1)-- The outside electrode in fixed paper-dielectric and ceramic-dielectric capacitors.
--(2)-- The moving element in adjustable and variable capacitors.

--(3)-- The low-potential element in feed-through capacitors.
(in English) (1993)  315-1975 - IEEE Standard American National Standard Canadian Standard Graphic Symbols for Electrical and Electronics Diagrams (Including Reference Designation Letters), IEEE, p. 24  DOI:  10.1109/IEEESTD.1993.93397. ISBN:  0738109479.
Michel Bakni