diff --git a/spec/Section 5 -- Validation.md b/spec/Section 5 -- Validation.md
index d16debb79..7afcbb303 100644
--- a/spec/Section 5 -- Validation.md	
+++ b/spec/Section 5 -- Validation.md	
@@ -1938,6 +1938,10 @@ A notable exception to typical variable type compatibility is allowing a
 variable definition with a nullable type to be provided to a non-null location
 as long as either that variable or that location provides a default value.
 
+In the example below, an optional variable `$booleanArg` is allowed to be used
+in the non-null argument `optionalBooleanArg` because the field argument is
+optional since it provides a default value in the schema.
+
 ```graphql example
 query booleanArgQueryWithDefault($booleanArg: Boolean) {
   arguments {
@@ -1946,7 +1950,12 @@ query booleanArgQueryWithDefault($booleanArg: Boolean) {
 }
 ```
 
-In the example above, an optional variable is allowed to be used in an non-null argument which provides a default value.
+In the example below, an optional variable `$booleanArg` is allowed to be used
+in the non-null argument (`nonNullBooleanArg`) because the variable provides
+a default value in the query. This behavior is explicitly supported for
+compatibility with earlier editions of this specification. GraphQL authoring
+tools may wish to report this is a warning with the suggestion to replace
+`Boolean` with `Boolean!` to avoid ambiguity.
 
 ```graphql example
 query booleanArgQueryWithDefault($booleanArg: Boolean = true) {
@@ -1956,10 +1965,5 @@ query booleanArgQueryWithDefault($booleanArg: Boolean = true) {
 }
 ```
 
-In the example above, a variable provides a default value and can be used in a
-non-null argument. This behavior is explicitly supported for compatibility with
-earlier editions of this specification. GraphQL authoring tools may wish to
-report this is a warning with the suggestion to replace `Boolean` with `Boolean!`.
-
 Note: The value {null} could still be provided to a such a variable at runtime.
 A non-null argument must produce a field error if provided a {null} value.