diff --git a/rdd-technical-reference.md b/rdd-technical-reference.md
index c76139b04ad2cc9abd67fafe580499cb08503bf1..4d9846b3cb538d41120d7dde70354e4a072b8706 100644
--- a/rdd-technical-reference.md
+++ b/rdd-technical-reference.md
@@ -126,6 +126,8 @@ Call diagrams can be useful to follow code and service calls and should be exist
 
 - meet and write documentation together regularly (documentation sprint)?
 
+- document REST-APIs using [openAPI](https://github.com/OAI/OpenAPI-Specification) if possible. OpenAPI docs should be located at /doc/api on servers
+
 ### Admin Documentation
 
 - how to install the software, how to run and/or restart it, how to test the installation, ...