Lincoln municipal code chapter 8.18 was properly signed into law by the Lincoln City council and mayor. Legislation rarely spells out literally everything they authorize, often giving officials appointed by elected officials leeway to set regulations within certain directives. No one in the legislature set where and the timings of red lights but instead they tell the Department of roads and other institutions to do it within regulations. 8.18 sets out that directive to the health director (who is appointed by two sets of elected officials and one set of appointed health experts (director Lopez was appointed unanimously with full knowledge she would implement DHMs that would include mask mandates)) in regards to the prevention of spread of communicable diseases. If you disagree that 8.18 gives this power to the director then the city council, the county commission, and the Nebraska courts all disagree with you.