544.15 Subscription and verification.
Every pleading may be verified in the manner following:
(1) By the affidavit of the party, or of one or more of the parties pleading together, that the affiant knows the contents of the pleading, that the averments thereof are true of affiant's own knowledge, save as to such as are therein stated on information and belief, and that as to those the affiant believes them to be true;
(2) If the party be a corporation, the affidavit may be made by any officer thereof having knowledge of the facts sworn to; if the state, or any officer thereof acting in its behalf, by the attorney general;
(3) If no party or officer acquainted with the facts and capable of making such affidavit be within the county where the attorney resides, the pleading may be verified by the attorney or agent of the party, stating the fact of such absence and that the pleading is true to the best of the verifier's knowledge and belief.