All contracts to which the city is a party, in addition to being signed by the Mayor and the City Manager, shall be sealed with the city's seal. The seal shall be kept in the custody of the City Manager and affixed by him or her. The official city seal shall be a circular disk having engraved thereupon, “The City of Waseca,” and other words, figures or emblems as the Council may, by resolution, designate.
(`86 Code, § 2.52)