diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-site/src/site/markdown/TimelineServiceV2.md b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-site/src/site/markdown/TimelineServiceV2.md
index 28c4a910512..f097b60b336 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-site/src/site/markdown/TimelineServiceV2.md
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-site/src/site/markdown/TimelineServiceV2.md
@@ -486,6 +486,8 @@ You can provide the flow context via YARN application tags:
 
     appContext.setApplicationTags(tags);
 
+Note : The Resource Manager converts YARN application tags to lowercase before storing them. Hence one should convert
+Flow names and Flow versions to lowercase before using them in REST API queries.
 
 ## Timeline Service v.2 REST API