# Supply formats overview

## CSV and GeoPackage <a href="#bookmark4" id="bookmark4"></a>

GeoPackage is an open, standard, platform-independent, portable, self-describing, compact format for transferring geospatial information. For more information on this format, please see the [Getting started with GeoPackage guide](/os-downloads/resources/product-resources/getting-started-with-geopackage-and-vector-tiles-guides/getting-started-with-geopackage.md).

The following tables give a comparison between the CSV attributes and the GeoPackage attribution:

### CSV attribution and format

| **Mnemonic** | **Description**                | **Data type** | **Size** |
| ------------ | ------------------------------ | ------------- | -------- |
| N/A          | N/A                            | N/A           | N/A      |
| PC           | Postcode                       | A8            | 8        |
| PQ           | Positional\_quality\_indicator | I2            | 2        |
| EA           | Eastings                       | I6            | \*       |
| NO           | Northings                      | I7            | \*       |
| CY           | Country\_code                  | A9            | 9        |
| RH           | NHS\_regional\_HA\_code        | A9            | 9        |
| LH           | NHS\_HA\_code                  | A9            | 9        |
| CC           | Admin\_county\_code            | A9            | 9        |
| DC           | Admin\_district\_code          | A9            | 9        |
| WC           | Admin\_ward\_code              | A9            | 9        |

### GeoPackage attribution and format

| **Description**                | **Data type** |
| ------------------------------ | ------------- |
| fid                            | int           |
| postcode                       | TEXT          |
| positional\_quality\_indicator | int           |
| N/A                            | N/A           |
| country\_code                  | TEXT          |
| nhs\_regional\_ha\_code        | TEXT          |
| nhs\_ha\_code                  | TEXT          |
| admin\_county\_code            | TEXT          |
| admin\_district\_code          | TEXT          |
| admin\_ward\_code              | TEXT          |

## CSV format

* Those fields containing text (A) will be enclosed by double quotes which have not been included in the sizes listed in the table above. An asterisk (\*) denotes variable length.
* Fields with null data will appear as "" for text and 0 for numeric.
* Each record will be terminated with a carriage return character (ASCII 13) and a line feed character (ASCII 10).

Example of a Code-Point Open CSV record:

"SO16 0AS",10,437292,115542,"E92000001","E19000002","E18000009","E10000014","E07000093","E05012936"

## GeoPackage format

Note that there are no Eastings or Northings in GeoPackage; the geometry is already created in the GeoPackage container and is not listed as data but will be seen as a column in a database (PostGIS) called *geometry* with a coordinate reference system of British National Grid

EPSG: 27700 for Great Britain (GB) postcodes.

Fields with a null value will appear as \[Null] for text (PostGIS) or as an empty field in a GIS. A null numeric value will appear as 0 in both a database and an attribute table in a GIS.

The screenshot below show an example of a Code-Point Open GeoPackage record taken from the Information tool in QGIS:

<figure><img src="/files/uYUKsyAGZGS27s2BU5Rx" alt="GeoPackage record as displayed in QGIS."><figcaption><p><em>GeoPackage record as displayed in QGIS.</em></p></figcaption></figure>


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