ADRIFT Developer must not be in Simple Mode for this tab to be visible on the main toolbar.
The Properties tab allows you to assign properties to the location. For example, you may want to say a location is a dark room (in which case you might need to have a light source handy to be able to view the location), or you might want to mark the location as being outside (in which case the location might be affected by time of day).
Selecting a property will assign it to the current location. Depending on the property type, this may just be a selection only property, or you may need to assign a value to it.
To use the value of a property in an expression or a text box, use a location function.
To add a new property, click the Add New Property button at the bottom of the form. This will bring up the New Property dialog box and default it to "Property of: Locations". Once the property has been applied, it should appear in the list.