(a) Known Persons. Unless the court orders otherwise, the petitioner shall give notice to those persons whose identity and interest in the property are known and to any others designated by the court by mailing to them by ordinary mail and by certified mail a copy of the petition and a show cause order issued pursuant to Rule 10-104.

(b) Unknown Persons. If the court is satisfied from an affidavit of attempts to contact, locate, and identify filed by the petitioner in the form set forth in Rule 10-203 that reasonable efforts have been made to ascertain the identity or whereabouts of a person, the court shall order that notice to those persons whose identity or whereabouts are unknown shall be made in the manner provided by Rule 2-122.

Source: This Rule is derived from former Rule V79 b and c and from Code, Estates and Trusts Article, § 1-103(b).