In a portable communication device, such as a cellular phone, an identification
data signal which includes both a directory number and a mail number of the other
party is automatically registered in a memory of the portable communication device
during a pause period in conversation. Both a bearer's directory number and mail
address are automatically also transmitted to the other party during the pause
period. This dispenses with manual complex operation for registering the directory
number and the mail address in each portable communication device.
