Property superclass used to hold information about how to populate this property.
POPORDER defines the order in which this property will be assigned a value. This should be an integer value.
If POPORDER is less than zero then the property will not be populated by the Populate method.
POPSPEC defines a 'value generator method' for a property.
It is used by the %Populate class to generate sample data.
The format of POPSPEC is this [::].