15 U.S.C. § 1692b

Any debt collector communicating with any person other than the consumer for the purpose of acquiring location information about the consumer shall— (1) identify himself, state that he is confirming or correcting location information concerning the consumer, and, only if expressly requested, identify his employer; (2) not state that such consumer owes any debt; (3) not communicate with any such person more than once unless requested to do so by such person or unless the debt collector reasonably believes that the earlier response of such person is erroneous or incomplete and that such person now has correct or complete location information; (4) not communicate by post card; (5) not use any language or symbol on any envelope or in the contents of any communication effected by the mails or telegram that indicates that the debt collector is in the debt collection business or that the communication relates to the collection of a debt; and (6) after the debt collector knows the consumer is represented by an attorney with regard to the subject debt and has knowledge of, or can readily ascertain, such attorney’s name and address, not communicate with any person other than that attorney, unless the attorney fails to respond within a reasonable period of time to communication from the debt collector.