County Assessor "Use codes" affect on Tax Assessment

[Lois S.]

What effect does the "use code" of a property have on the tax assessment?

For example, I see that the use code on a property that I know is being rented out is not listed as a multi-family rental, even though it's been sub-divided by the owner.  It's still listed as a single-family residential property.

The county assessor apparently didn't update the code when the property was sold several years ago.