The call forwardThe call forward (CF) feature when activated will route your call automatically to a number other than the number dialed. However,  two types of call forwarding are regional call forwarding, and call forwarding variable. Call forwarding is activated through using the CO number, or by dialing *72 or... busy feature is used in conjunction with voice mail when your line is busy. This in turn activates the call forward busy function and the caller reaches the predetermined number (or voicemail) instead of a busy line. Sometimes LEC uses *90 to activate and *91 to deactivate.