The name of an electric cooperative which engages in the furnishing of telephone service may include the word "telephone" and need not include the word "electric" if it is not engaged in the furnishing of electrical energy. The words "telephone" and "cooperative" shall not both be used in the name of any corporation hereafter organized under the laws of, or authorized to transact business in, this state, except a cooperative or corporation transacting business in this state pursuant to the provisions of this article.