Here's the official code from the city website.
SECTION 215.290: DISPLAYING A DEADLY WEAPON
A. Any person who commits the offense of displaying a deadly weapon shall, upon conviction, be punished as provided by ordinance.
B. A person commits the offense of displaying a deadly weapon if such person exhibits, in the presence of one (1) or more persons, any weapon readily capable of lethal use in an angry or threatening manner. (CC 1999 §16-45; Ord. No. 03-68 §1, 10-13-03)
If I read it correctly, it addresses brandishing and not holstered open carry.