Census of India: Location Code structure

The general pattern followed in coding of any geographical unit was a serpentine one, beginning from the Northwest corner and completing at the farthest Southeast corner within the defined higher level of the geographical hierarchy. In so far as the state/union territory is concerned Jammu & Kashmir has code number 01 and code number 35 has been allotted to the union territory of Andaman & Nicobar Islands. Generally, the administrative jurisdiction below a district is a sub-district, for example, a tahsil or a taluk. However, in certain states and union territories exceptions had to be made since the nomenclature for sub-districts is not uniform throughout the country. For example, in Orissa Police station is the sub-district, in West Bengal it is the community Development Block and so on.

In Assam, Mizoram and Orissa there are a few sub-districts which cut across the district jurisdictions: In such situations the sub-districts have been provided a separate series of code numbers viz. 9000, 9001 and so on.

One of the major initiatives taken in the Census 2001 was the allotment of Permanent Location Code Number (PLCN) to each and every village within the State and not within a tahsil as in the earlier censuses. PLCN was thus assigned as one continuous number from the first village in the first district to the last village in the last district. PLCN is an eight digit unique location code number with the first six digits representing the code number of the village and the last two digits depicting two zeros '00'. These zeros are reserved as buffer to be used for coding any new village(s) that may come up between two villages in future. For example, if a new village comes up between two villages with PLCNs 01254600 and 01254700, the new village will be allotted PLCN 1254601 and so on. .

The location code number for a town is also an eight digit number starting with the digit 4 situated at the extreme left acting as the unique identifier. The next two digits depict the code number of the district in which the town falls followed by two digits representing the town serial number in the district. There are three zeros at the end as buffer, mainly to meet the requirement for bringing the number of digits to eight to match the number of digits in the PLCN for the villages. Thus a town location code number 40305000 represents the town serial number 5 of the district number 03 in a State.

The out-growths of towns have not been given any independent location code numbers. These have been given notional ward codes after the last ward code of the respective towns.