Per RCW 9.41.290 (state preemption of firearm laws), divisions of local government (city, county, town, or other municipality) cannot regulate firearms more restrictively than the state does. Exceptions to state preemption — that is, areas in which local governments are allowed to regulate firearms — are contained in RCW 9.41.300. These exceptions include:
"Restricting the discharge of firearms in any portion of their respective jurisdictions where there is a reasonable likelihood that humans, domestic animals, or property will be jeopardized. Such laws and ordinances shall not abridge the right of the individual guaranteed by Article I, section 24 of the state Constitution to bear arms in defense of self or others."
"Restricting the possession of firearms in any stadium or convention center, operated by a city, town, county, except that such restrictions shall not apply to [concealed pistol license holders, law enforcement officers, or any] showing, demonstration, or lecture involving the exhibition of firearms."
"Restricting the areas in their respective jurisdictions in which firearms may be sold."
I think you have to look at the entire statement in the RCW.
Restricting the possession of firearms in any stadium or convention center, operated by a city, town, county, except that such restrictions shall not apply to [concealed pistol license holders, law enforcement officers, or any] showing, demonstration, or lecture involving the exhibition of firearms
This seems to change the actual interpretation of the regulation. It may read as the restriction does not apply if you are showing, demonstrating, or lecturing involving the exhibition of firearms.
Not too sure about how to read the RCW.
Dave