包含惯例，在将IEC 60617应用于实际设备目录的符号时很有用，并显示了在标准中提供替代技术时的首选选项。它还有助于创建外观尽可能一致的符号，而不依赖于发起人，同时仍能准确地表示功能。

Contains conventions, helpful when applying IEC 60617 to symbols for catalogues of real devices, and shows preferable choices where alternative techniques are provided in the standard. It also helps to create symbols having as consistent an appearance as possible, not depending on the originator, while still accurately representing the function.