The second tutorial in PropertyWizard Help introduces the idea of using element properties in your formulas:
You can refer to:
Properties of the target element – Use the name shown in the Revit Properties window, as in this example. If the name includes spaces or special characters, then you need to wrap it in square brackets like this: [Sheet Name].
Nested properties – Use ‘dot notation’ like Dynamo. For example, the name of a Door’s Level would be Level.Name. There is no limit to the depth of nesting, but all the properties except the last must be Elements or ElementIDs.
API properties of the target element or nested elements – These are the ‘behind the scenes’ properties exposed in the Revit API, which you can find using the Revit Lookup add-in or the Revit API Help. Use the property name, e.g. Location for an element’s Location property.
Project Information properties – Use ProjectInfo.parametername.
Global Parameters – Use GlobalParameter.parametername.