Tex. Family Code § 102.010

(a) Except as provided by Section 17.032, Civil Practice and Remedies Code, citation may be served to persons entitled to service of citation who cannot be notified by personal service or registered or certified mail and to persons whose names are unknown by publication on the public information Internet website maintained as required by Section 72.034, Government Code, and in a newspaper of general circulation published in the county in which the petition was filed.

(b) Citation by publication shall be published not later than the 20th day before the date set for the hearing. One or more causes to be heard on a certain day may be included in one notice and hearings may be continued from time to time without further notice.

(c) Citation by publication shall be sufficient if given in substantially the following form:

"You have been sued. You may employ an attorney. If you or your attorney do (does) not file a written answer with the clerk who issued this citation by 10 a.m. on the Monday next following the expiration of 20 days after you were served this citation and petition, a default judgment may be taken against you. The petition of ______________, Petitioner, was filed in the Court of _______________ County, Texas, on the ___ day of _________, _____, against __________, Respondent(s), numbered _____, and entitled 'In the interest of __________, a child (or children).' The suit requests (statement of relief requested, e.g., 'terminate the parent-child relationship'). The date and place of birth of the child (children) who is (are) the subject of the suit: _____________.

"The court has authority in this suit to render an order in the child's (children's) interest that will be binding on you, including the termination of the parent-child relationship, the determination of paternity, and the appointment of a conservator with authority to consent to the child's (children's) adoption.

"Issued and given under my hand and seal of the Court at _________, Texas, this the ___ day of _______, ____.

(d) In any suit in which service of citation is by publication, a statement of the evidence of service, approved and signed by the court, must be filed with the papers of the suit as a part of the record.

(e) In a suit filed under Chapter 161 or 262 in which the last name of the respondent is unknown, the court may order substituted service of citation by publication, including publication by posting the citation at the courthouse door for a specified time, if the court finds and states in its order that the method of substituted service is as likely as citation by publication on the public information Internet website maintained as required by Section 72.034, Government Code, or in a newspaper in the manner described by Subsection (b) to give the respondent actual notice of the suit. If the court orders that citation by publication shall be completed by posting the citation at the courthouse door for a specified time, service must be completed on, and the answer date is computed from, the expiration date of the posting period. If the court orders another method of substituted service of citation by publication, service shall be completed as directed by the court.