diff --git a/docs/viewtoken.md b/docs/viewtoken.md
index bc86d04757c..662a6f10f98 100644
--- a/docs/viewtoken.md
+++ b/docs/viewtoken.md
@@ -22,6 +22,8 @@ title: ViewToken Object Type
 
 Unique numeric identifier assigned to the data element.
 
+When it does not return any value as a parameter it may come as null.
+
 | Type   | Optional |
 | ------ | -------- |
 | number | Yes      |