specially concurring.
I agree that service by a nonattorney of the amended protection order by ordinary mail is sufficient under Rule 5 of the North Dakota Rules of Civil Procedure and was proved by sufficient evidence. I therefore concur in the result and in that portion of the majority opinion that analyzes the sufficiency of the evidence and Rules 4 and 5 of the North Dakota Rules of Civil Procedure.
Unchallenged jury instructions become the law of the case. Bartholomay v. St. Thomas Lumber Co., 148 N.W.2d 278 (N.D.1966); Cochrane v. Nat’l Elevator Co., 20 N.D. 169, 127 N.W. 725 (1910). Because no jury instruction defining the word “serve” or “service” was requested or given, I agree that, under the law of the case, the term “serve” in NDCC § 14^07.1-06 is to be understood in its “ordinary” sense. Usually, however, “service” is a word of art, a “technical” word, see NDCC § 1-02-03, that has “acquired a peculiar and appropriate meaning in law.” See id. That peculiar and appropriate meaning is to be found in Rules 4 and 5 of the North Dakota Rules of Civil Procedure.