Subtype Usage
POSITIVEAllows only positive integers to be stored, up to the maximum of 2,147,483,647. Zero is not considered a positive number, and so is not an allowed value.
NATURALAllows only natural numbers to be stored, which includes zero. Allowed values are 0, 1, 2, 3, and so on up to the maximum of 2,147,483,647.
POSITIVEnLike POSITIVE but cannot be null.
NATURALnLike NATURAL but cannot be null.
SIGNTYPERestricts a variable to only the values -1, 0, and 1.