(a) If notice of hearing on a motion or other proceeding is required, the notice may be given in the manner prescribed by law or the Texas Rules of Civil Procedure, or, alternatively, notice may be given to any party or to his attorney if the party has appeared by attorney or requested that notice be sent to his attorney.
(b) If the address or identity of a party is not known and cannot be ascertained with reasonable diligence, on order of the court notice may be given by publishing a copy of the notice at least three times in a newspaper having general circulation in the county where the hearing is to be held. The first publication of the notice must be at least 10 days before the time set for the hearing. If there is no newspaper of general circulation in the county where the hearing is to be held, the publication shall be made in a newspaper of general circulation in an adjoining county.