From the Global Objects menu, select
Property Class Extension.
In the lower left corner of the Property Class Extensions
editor, click the New (+) button.
In the Name field of the
New form, specify a name for the new Property Class
Extension object.
Click OK.
The new Property Class Extension name displays in the list on the left panel,
and the Properties panel on the right
displays the property sheet for the new Property Class Extension object.
In the property sheet, specify the properties and attributes to be used by the
new Property Class Extension object.
To save the Property Class Extension as a new object, click OK.