It eliminated the geographical significance of the first three digits of the SSN, referred to as the area number, by no longer allocating specific numbers by state for assignment to individuals. It eliminated the significance of the highest group number assigned for each area number, and, as a result, the High Group List is frozen in time and can be used for validation of only those SSNs issued prior to the randomization implementation date (see section "Valid SSNs"). Previously unassigned area numbers have been introduced for assignment, excluding area numbers 000, 666 and 900–999.