Indiana Code Title 34. Civil Law and Procedure § 34-15-4-2

Sec. 2. (a) Before bringing a suit described in section 1 of this chapter, the aggrieved party shall:

serve notice in writing specifying the factual statements in the article that are alleged to be false and defamatory, and correcting the falsity of the statements by reference to the true facts.

(b) If the publication of the alleged libel was by a newspaper, the notice shall be served on the publisher at the newspaper's principal office of publication.  If the transmission of the alleged libel was by a news service, the notice shall be served on the bureau chief at the news service's principal Indiana office.