Del. Fam. Ct. R. Civ. P. 221
Personal service of process shall be done in accordance with Civil Rule 4(d)(1) through (5) and 4(e) of this Court. In the event that personal service cannot be accomplished on the respondent or DSCYF files an affidavit alleging that personal service cannot be accomplished on the respondent in this state for the reasons set forth in the affidavit, DSCYF shall then cause to be published notice of the action informing the respondent they shall have twenty (20) days to file an answer, move or otherwise plead in the action. This notice shall be published on a legal notices website established by the Court or in a newspaper in the locality in which the respondent is or was believed to last be located. Failure to obtain service of process over one party by the time any hearing occurs shall not prevent the Court from proceeding to a hearing as to any other party over whom jurisdiction has been obtained. DSCYF shall make continuing, diligent efforts to locate and notify the parents who have not been personally served.
Del. Fam. Ct. R. Civ. P. 221