diff --git a/tests/data/README.md b/tests/data/README.md
index ae7140e..0d06a72 100644
--- a/tests/data/README.md
+++ b/tests/data/README.md
@@ -77,7 +77,7 @@ This directory provides test data to demonstrate functionality.
 - License: https://www.canada.ca/en/transparency/terms.html
 - Notes
   - ISO records transformed to OGC API - Records GeoJSONs with `tests/load_tinydb_records.py`
-  
+
 ### `dutch_addresses_*`
 - source: Dutch Kadaster
 - URL: https://geodata.nationaalgeoregister.nl/inspireadressen/wfs?request=GetCapabilities&service=wfs (discontinued, see below)
@@ -87,3 +87,11 @@ This directory provides test data to demonstrate functionality.
   - address-records derived by Kadaster from the Dutch "Buildings and Addresses" key registry (BAG)
   - WMS is still available: https://service.pdok.nl/kadaster/adressen/wms/v1_0?request=GetCapabilities&service=WMS
   - raw dataset BAG (GML, about 2GB) can always be downloaded via the [Atom Feed](https://service.pdok.nl/kadaster/adressen/atom/v1_0/index.xml)
+
+### `items.geojson`
+- source: Wikipedia
+- URL: https://en.wikipedia.org/wiki/GeoJSON#Geometries
+- License: CC0 3.0 https://creativecommons.org/licenses/by-sa/3.0/
+- Notes
+  - `items.geojson` tests pygeoapi's capability to serialize all geometry types for individual collection items in [JSON-LD formats](https://docs.pygeoapi.io/en/latest/configuration.html#linked-data), including GeoSPARQL WKT and schema.org/geo.
+  - The features represent the range of geoJSON geometry types, instead of real locations. Additionally, each feature has a uri defined in the properties block.