Almost all data fields have a FieldClass property. FieldClass has as much effect on the content and usage of a data field as the data type; in some instances, it has more effect. In the next chapter, we'll cover most of the field properties, but we'll discuss the FieldClass property options now.
When the FieldClass is Normal, the field will contain the type of application data that's typically stored in a table—the contents we would expect based on the data type and various properties.
FlowFields must be dynamically calculated. FlowFields are virtual fields that are stored as metadata; they do not contain data in the conventional sense. A FlowField contains the definition of how to calculate (at runtime) the data that the field represents and a place to store the result of that calculation. Generally, the Editable property for a FlowField is set to No..
Depending on the CalcFormula method, this could be a value, a reference...