A more sophisticated classification was developed for woodlands in Scotland due to the nature of the available historical sources. IMPORTANT. For Scottish woods, the category Ancient comprises woods recorded as being of semi-natural origin on EITHER the 1750 Roy maps OR the 1st Edition Ordnance Survey maps of 1860. This is due a) to the likelihood of the latter having been omitted from the Roy maps and b) to render the Scottish classification compatible with that for England and Wales. More information at the [NatureScot website](https://www.nature.scot/doc/guide-understanding-scottish-ancient-woodland-inventory-awi) [Complete metadata](https://spatialdata.gov.scot/geonetwork/srv/eng/catalog.search;jsessionid=19161E105FFC9820365BD50CBE70F689#/metadata/A091F945-F744-4C8F-95B3-A09E6EF6AE33)