An ordinal is a named set of ordered values. Using the DEFINE ORDINAL statement, you can define an ordinal and assign meaningful names to be used to refer to that set. For example, you can define an ordinal called "color". The "color" ordinal could include the members "red", "yellow", "blue", etc. The members of the "color" set can then be referred to by these names instead of by their associated fixed binary value, making code much more self-documenting. Furthermore, a variable declared with the ordinal type can be assigned and compared only with an ordinal of the same type, or with a member of that ordinal type. This automatic checking provides for better program reliability.