Shipping calculations residential or commercial?

Does the Embeddable Module Instant Pricing use the base of Residential or Commercial to calculate the price for Live UPS shipping? It makes a few $ difference so would like to know. The module is based on State/Zip only.

It's automatic, but as a base it's Commercial.
I read in the UPS API that you need to specifically pass a param to get Residential instead.
Found here:
https://catalinatechnology.com/message.aspx?messageGUID=d6348c3c-8b8d-46da-9450-a4600fb128cf