A communication terminal includes a communication interface configured to
exchange data via a communication network, a memory, a first table stored
in the memory and configured to store identifiers of communication
terminals which are senders of received data, a second table stored in
the memory and configured to store identifiers of communication terminals
designated by a user, a user interface configured to receive an input of
an identifier of a communication terminal with which a communication is
to be initiated, and a processor configured to determine whether the
identifier of the communication terminal input via the user interface is
stored in the first table, determine whether the input identifier of the
communication terminal is stored in the second table, and if a result of
the determination is affirmative, instruct the communication network not
to notify an identifier of its own terminal to the communication
terminal.