Go to the “more info” screen for the page where you entered the real estate property.
(That is: Client Info > Assets & Debts > Add Real Estate Property > More Info.)
Scroll down to the section on Separate Property.
You will see the Moore-Marsden link there.
This calculation implements the formula specified by the California courts for calculating the separate property portion of a residence.
We do not see the economic logic of this calculation, so we are not really able to explain or justify it.