> 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/land-and-terrain-portfolio/os-mastermap-sites-layer/os-mastermap-sites-layer-getting-started-guide/cadcorp-sis-desktop.md).

# Cadcorp SIS Desktop

These instructions are based on Cadcorp SIS Desktop version 9.0 and assume you have set the default coordinate reference system to British National Grid (EPSG 27700). The instructions are also valid for the free, read-only version, Cadcorp SIS Desktop Express.

## Loading and displaying the GML supply <a href="#id-3.1-loading-and-displaying-the-gml-suppl" id="id-3.1-loading-and-displaying-the-gml-suppl"></a>

To load and display GML data in Cadcorp SIS Desktop:

1. Open an existing map or create a new one.
2. In *Home*, click *Add Overlay*.
3. In the Overlay Types dialog:
   * Files: Select *File* and click *Next*.<br>

     <figure><img src="/files/Ftmsp3OIx9cXFkp1tdph" alt="Cadcorp Overlay Types dialog showing the  Files > File option."><figcaption><p>Cadcorp Overlay Types dialog showing the Files > File option.</p></figcaption></figure>
   * Navigate to and select the file on your computer and click *Finish*.

*Your GML data now displays in both the Maps panel and map area. The data is un-styled and will look similar to the following image:*

<figure><img src="/files/dS6hCJhoHWX2foVX7KGZ" alt="Cadcorp UI showing GML data in the Maps navigation panel and graphical interface." width="563"><figcaption><p>Cadcorp UI showing GML data in the Maps navigation panel and graphical interface.</p></figcaption></figure>


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