diff --git a/S3-Nginx-Proxy.md b/S3-Nginx-Proxy.md
index 088af2a..e63fc45 100644
--- a/S3-Nginx-Proxy.md
+++ b/S3-Nginx-Proxy.md
@@ -11,6 +11,8 @@ Additionally, make sure that `proxy_request_buffering` is `off` (default is `on`
 
 ```
 upstream seaweedfs { 
+        # Hash on uploadId query string in the GET request create consistency for multipart uploads,
+        # only necessary when using local embedded filer store (leveldb)
 	hash $arg_uploadId consistent;
 	server localhost:8333 fail_timeout=0; 
 	keepalive 20;