(34) When end-users who are natural persons have provided their consent to receiving direct marketing communications, they should still be able to withdraw their consent at any time in an easy manner and without any cost to them. To facilitate effective enforcement of Union rules on direct marketing communications, it is necessary to prohibit the masking of the identity and the use of false identities, false return addresses or numbers while sending or presenting direct marketing communications. Direct marketing communications should therefore be clearly recognizable as such and should indicate the identity of the legal or the natural person sending the communication or on behalf of whom the communication is sent and provide the necessary information for end-users who are natural persons to exercise their right to withdraw their consent to receiving further direct marketing communications, such as valid contact details (e.g. link, e-mail address) which can be easily used by end-users who are natural persons to withdraw their consent free of charge.