This type alows you to model information which takes one of predefined values. There is not really an enumerated type (like BOOLEAN could be); instead, you can define your own one, such as:
DaysOfTheWeek ::= ENUMERATED {
sunday(0), monday(1), tuesday(2), wednesday(3), thursday(4), friday(5), saturday(6)
}
Priority ::= ENUMERATED {low(-1), medium(0), high(1)}
Although the notation is simmilar to notation of integers with distinguished values, there are some important differencies, besides the use of keyword ENUMERATED:
Thus it is purely correct to ommit those numbers in definitions. On the other hand, numbers are included, because of compatibility.