Under a transitional arrangement following reunification , between NUMBER@1 and NUMBER@2 postal codes in the west were prefixed with ` W ' , e.g. : W-1000 LOCATION@1 NUMBER@3 -LRB- postal districts in western cities were separate from the postal code -RRB- and those in the east with ` O ' -LRB- for MISC@1 -RRB- , e.g. : O-1xxx LOCATION@1 .

Between NUMBER@1 and NUMBER@2 postal codes in the west started with W , eg W-1000 LOCATION@1 NUMBER@3 -LRB- postal districts in western cities were separate from the postal code -RRB- and those in the east with O -LRB- for MISC@1 -RRB- , eg : O-1234 LOCATION@1 .
