The design of an application should begin at the simplest level, with the design of the data elements. The type of data our development tool supports has a significant effect on our design. Because NAV is designed for financially-oriented business applications, NAV data types are financially and business oriented.

In this chapter, we will cover many of the data types we use within NAV. For each data type, we will cover some of the more frequently modified field properties and how particular properties, such as Field Class, are used to support application functionality. Field Class is a fundamental property which defines whether the contents of the field are data to be processed or control information to be interpreted. In particular, we will be covering:

• Basic definitions
• Fields
• Data types
• The FieldClass properties
• Filtering