diff --git a/features.md b/features.md
index 18842e309..ea8364a46 100644
--- a/features.md
+++ b/features.md
@@ -138,6 +138,18 @@ Annotations MUST be a key-value map that follows the same convention as the Key
 }
 ```
 
+## <a name="featuresUnsafeAnnotationPrefixes" />Unsafe annotation prefixes
+
+**`unsafeAnnotationPrefixes`** (array of strings, OPTIONAL) contains prefixes of the [`annotations` property of `config.json`](config.md#annotations)
+that may change the behavior of the runtime.
+
+### Example
+```json
+"unsafeAnnotationPrefixes": {
+  "org.systemd.property."
+}
+```
+
 # Example
 
 Here is a full example for reference.