> For the complete documentation index, see [llms.txt](https://docs.os.uk/os-downloads/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.os.uk/os-downloads/products/areas-and-zones-portfolio/boundary-line/boundary-line-technical-specification/shapefile-tab-and-gkpg/layers-shapefile-tab-and-gkpg/tab.md).

# TAB

The TAB format (MapInfo tables) is the native format of MapInfo. This format can be read into most GIS packages. The TAB format consists of two files for tabular information, similar to a spreadsheet, and two files for geographic display. All four files are needed to display the geometry and attributes of geographically reference features. The four specific file extensions needed to display the geometry are as follows:

`.dat`: The dBASE file that stores the attribute information of features.

`.id`: The file that stores the index of the feature geometry to the attribute table.

`.map`: The file that stores the geographic information to display each feature.

`.tab`: The file that links the above three files and holds information about the dataset.

## List of layers <a href="#id-4.2-list-of-layers" id="id-4.2-list-of-layers"></a>

<table><thead><tr><th width="303">Layer</th><th width="131">Country</th><th>Description</th></tr></thead><tbody><tr><td>county (inc GLAs)</td><td>E</td><td>Polygon</td></tr><tr><td>county_electoral_division</td><td>E</td><td>Polygon</td></tr><tr><td>district_borough_unitary</td><td>E, S, W</td><td>Polygon</td></tr><tr><td>district_borough_unitary_ward</td><td>E, S</td><td>Polygon</td></tr><tr><td>english_region</td><td>E</td><td>Polygon</td></tr><tr><td>greater_london_const</td><td>E</td><td>Polygon</td></tr><tr><td>high_water</td><td>E, S, W</td><td>Polyline</td></tr><tr><td>parish</td><td>E, S, W</td><td>Polygon</td></tr><tr><td>unitary_electoral_division</td><td>E, W</td><td>Polygon</td></tr><tr><td>westminster_const</td><td>E, S, W</td><td>Polygon</td></tr><tr><td>scotland_and_wales_const</td><td>S, W</td><td>Polygon</td></tr><tr><td>scotland_and_wales</td><td>S, W</td><td>Polygon</td></tr><tr><td>polling_districts_england_region</td><td>E</td><td>Polygon</td></tr><tr><td>Boundary_line_historic_counties_region</td><td>E, S, W</td><td>Polygon</td></tr><tr><td>Boundary_line_ceremonial_counties_region</td><td>E, S, W</td><td>Polygon</td></tr><tr><td>community_ward</td><td>W</td><td>Polygon</td></tr><tr><td>historic_european_region</td><td>E, S, W</td><td>Polygon</td></tr><tr><td>country_region</td><td>E, S, W</td><td>Polygon</td></tr></tbody></table>


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