A postal code or a pattern of the form prefix* denoting the inclusive
upper bound of the range defining the area. It must have the same length
as postalCodeRangeBegin: if postalCodeRangeBegin is a postal code then
postalCodeRangeEnd must be a postal code too; if postalCodeRangeBegin
is a pattern then postalCodeRangeEnd must be a pattern with the same
prefix length. Optional: if not set, then the area is defined as being all
the postal codes matching postalCodeRangeBegin.