> 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/maps-and-imagery-portfolio/os-mastermap-topography-layer/os-mastermap-topography-layer-technical-specification/file-naming.md).

# File naming

## GeoPackage file naming <a href="#id-1.5.1-geopackage" id="id-1.5.1-geopackage"></a>

If GeoPackage format is selected, the filename will be constructed as: OSMasterMapTopography\_gpkg\_<*order number*>.zip

Where:

* order number is your customer order number.

Within the zip file, there will be a Data folder (containing six GeoPackage files – one file per feature type)

and a Doc folder (containing licence and readme files):

* Data folder
  * OSMasterMapTopography\_<*order number*>\_boundary\_line.gpkg
  * OSMasterMapTopography\_<*order number*>\_cartographic\_symbol.gpkg
  * OSMasterMapTopography\_<*order number*>\_cartographic\_text.gpkg
  * OSMasterMapTopography\_<*order number*>\_topographic\_area.gpkg
  * OSMasterMapTopography\_<*order number*>\_topographic\_line.gpkg
  * OSMasterMapTopography\_<*order number*>\_topographic\_point.gpkg
* Doc folder: \<licence and readme files>

## Vector tiles file naming

If vector tiles format is selected, the file name will be constructed as: OSMasterMapTopography\_mbtiles\_gb.zip

Within the zip file, there will be a Data folder (containing six MBTiles files – one file per feature type) and a Doc folder (containing licence and readme files):

* Data folder
  * OSMasterMapTopography\_gb\_BoundaryLine.mbtiles
  * OSMasterMapTopography\_gb\_CartographicSymbol.mbtiles
  * OSMasterMapTopography\_gb\_CartographicText.mbtiles
  * OSMasterMapTopography\_gb\_TopographicArea.mbtiles
  * OSMasterMapTopography\_gb\_TopographicLine.mbtiles
  * OSMasterMapTopography\_gb\_TopographicPoint.mbtiles
* Doc folder: \<licence and readme files>

## GML file naming <a href="#id-1.5.3-gml" id="id-1.5.3-gml"></a>

### **Geographic chunks (zipped)**

If geographic chunk data supply is used, the file name will be constructed as: orderNumber-ngxxyy.gz Where:

* orderNumber is your customer order number.
* ngxxyy is the chunk name plus the four-digit grid reference belonging to the 1km south-west corner of the 2km / 5km / 10km chunk being supplied.

For example: 1234567-SU4020.gz

### **Non-geographic chunks (zipped)**

If non-geographic chunk data supply is selected, the file name will be constructed as: orderNumber- vvvvvv.gz

Where:

* orderNumber is your customer order number.
* vvvvvv is the volume number of the file.

For example: 1234567-000001.gz


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