Fix unintentionally altered meaning

pushrax · pushrax · commit c3eccce97c45 · 2015-07-07T15:28:33.000-04:00
diff --git a/Section 5 -- Validation.md b/Section 5 -- Validation.md
@@ -425,7 +425,7 @@ fragment goodNonNullArg on Arguments {
 
 ```
 
-A field with a nullable argument can be omitted.
+The argument can be omitted from a field with a nullable argument.
 
 Therefore the following query is valid:
 
