“Ｒ”键与“ｆｌａｓｈ”键的区别及使用中应注意的问题□成维和１“Ｒ”键与“ｆｌａｓｈ”键的区别“Ｒ”键是双音频电话机上为配合程控交换机的服务功能而设的一个键，称作“重新呼叫”键．通过使用“Ｒ”键可以在程控交换机上实现如转移呼叫、三方通话及遇忙回叫等功... Differences between “R” key and “flash” key and problems to be noticed □ Difference between Cheng-dimensional and 1 “R” key and “flash” key “R” key is the service function of dual-tone telephone in order to cooperate with the program- Set a key, called the “call again” button. Through the use of “R” key on program-controlled switches such as transfer calls, three-way calling and busy callback ...