> 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.md).

# Boundary-Line Technical Specification

This technical specification provides detailed technical information about Boundary-Line. It is targeted at technical users and software developers.

Boundary-Line provides a representation of the hierarchy of administrative and electoral boundaries and their names for England, Scotland and Wales. Boundary-Line for England and Wales was initially digitised from Ordnance Survey’s boundary record sheets at 1:10 000 scale (or, in some cases, at larger scales).

The Government Statistical Service (GSS) codes are supplied by the Office for National Statistics (ONS) and General Register Office for Scotland (GROS).

Appropriate software is needed to use the data for your intended application.

## Index

This technical specification includes the following sections:

* [Shapefile, TAB and GPKG](/os-downloads/products/areas-and-zones-portfolio/boundary-line/boundary-line-technical-specification/shapefile-tab-and-gkpg.md)
* [GML](/os-downloads/products/areas-and-zones-portfolio/boundary-line/boundary-line-technical-specification/gml.md)
* [Vector Tiles](/os-downloads/products/areas-and-zones-portfolio/boundary-line/boundary-line-technical-specification/vector-tiles.md)


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