If you heavily use property sets then at one time or another you have found the need to schedule a property that is not readily available via an automatic property definition. For example when creating a pipe system you can assign it a system family (commonly known as group) that will allow different systems of the same family to interconnect. Systems that are not of the same group will not interconnect. This could be a handy property to schedule but how do you do it? System group is not an automatic property of MEP objects.
First start the style manager and then open up the property set that you wish to add the system family definition to. The first thing that needs to be done is to add the automatic property definition ObjectID to the property set. This is needed to access information about the object. Then just add the following code to a formula based property definition:
Make sure to input [ObjectID] by clicking on the definition in the Insert Property Definition section in the lower left portion of the dialog window. Hit Ok and make sure to make your new property definition viewable so you can see it on the property palette’s extended tab.