The habitatmap_stdized.gpkg file is a processed version of the Natura 2000 habitat map of Flanders (De Saeger et al., 2018). It contains all polygons with Natura 2000 habitat types or regional important biotopes (RIB). This file is used as basis for designing monitoring schemes in Flanders. In the original habitat map, every polygon can consist of maximum 5 different vegetation types. This information is stored in the columns HAB1, HAB2,., HAB5 of the attribute table. The fraction of each vegetation type within the polygons is stored in the columns PHAB1, PHAB2, ., PHAB5. The habitatmap_stdized.gpkg file is a GeoPackage that contains: habitatmap_polygons: a spatial layer with every habitat map polygon that contains a Natura 2000 habitat or RIB type. habitatmap_types: a table with information on the habitat and RIB types (HAB1, HAB2,., HAB5) that occur within each polygon of habitatmap_polygons. The processing of the habitatmap_types table included following adjustment: For some polygons the vegetation type is uncertain, and the vegetation code in the raw habitatmap data source consists of 2 or 3 possible types, separated with a ','. The different possible vegetation types are split up and one row is created for each of them. The variable certain will be FALSE if the original vegetation code consists of 2 or 3 possible vegetation types, and TRUE if only one vegetation type is provided. The R-code for creating the habitatmap_stdized data source can be found in the GitHub repository 'n2khab-preprocessing' at commit 5f738b3f. A reading function to return the data source in a standardized way into the R environment is provided by the R-package n2khab.