diff --git a/documentation/design/05-implementation.md b/documentation/design/05-implementation.md
index 149512ab6b9278fbc5ffa51d0bb417b5d54d94d5..52b51866f9316161b6a948bcad0b13f6eceb32ee 100644
--- a/documentation/design/05-implementation.md
+++ b/documentation/design/05-implementation.md
@@ -25,4 +25,10 @@ The RESTCONF  client stubs used by goSDN are generated from YANG files using YGO
 
 ### Dependencies
 
-For now we can only use the OpenAPI 2.0 standard. This is because `go-swagger` does not support OpenAPI 3.0 specifications yet.
\ No newline at end of file
+For now we can only use the OpenAPI 2.0 standard. This is because `go-swagger` does not support OpenAPI 3.0 specifications yet.
+
+## Storing Information
+
+There seem to be two classes of information to be stored in the controller:
+* short-living information, such as, current topology 
+* long-time information, such as, information about principle network domains, elements in such a domain, etc