diff --git a/docs/reference/ois/next/specification.md b/docs/reference/ois/next/specification.md
index cac5099a..3859cf41 100644
--- a/docs/reference/ois/next/specification.md
+++ b/docs/reference/ois/next/specification.md
@@ -522,8 +522,9 @@ following elements:
 
 #### 5.5.1. `operationParameter`
 
-(Required) An object that refers to a parameter of an API operation, has the
-following elements:
+(Optional) An object that refers to a parameter of an API operation and has the
+below elements. Note that if omitted, the `parameter` will not be included as
+part of the request to the API endpoint.
 
 - `name`
 - `in`