Where by statute or these rules citation by publication is authorized and the statute or rules do not specify the requisites of such citation or the method of service thereof, or where they direct that such citation be issued or served as in other civil actions, the provisions of these rules shall govern. Where, however, the statute authorizing citation by publication provides expressly for requisites of such citation or service thereof, or both, differing from the provisions of Rules 114, 115, and 116, these rules shall not govern, but the special statutory procedure shall continue in force; provided, however, that Rule 117a shall control with respect to citation in tax suits.