Document minimal version for metadata through the API

diff --git a/docs/markdown/httpapi/api_spec.md b/docs/markdown/httpapi/api_spec.md
index 5d1bc62be44fe85316b247d14a935a2e1025bf35..9e75ce7c2b2a9c6fe6e8392caa772228dc664d93 100644 (file)
--- a/docs/markdown/httpapi/api_spec.md
+++ b/docs/markdown/httpapi/api_spec.md
@@ -605,6 +605,8 @@ Return format:
 Zone Metadata
 =============
 
+**Note:** Available since PowerDNS Authoritative Server 4.1.0.
+
 zone\_metadata\_resource
 ------------------------