diff --git a/spec/formatting.md b/spec/formatting.md
index c8179ef12d..da33ed5853 100644
--- a/spec/formatting.md
+++ b/spec/formatting.md
@@ -216,9 +216,10 @@ the following steps are taken:
    - If the _option_'s right-hand side successfully resolves to a value,
      bind the _identifier_ of the _option_ to the resolved value in the mapping.
    - Otherwise, bind the _identifier_ of the _option_ to an unresolved value in the mapping.
+     Implementations MAY later remove this value before calling the _function_.
      (Note that an Unresolved Variable error will have been emitted.)
-4. Remove from the resolved mapping of _options_ any binding for which the value is an unresolved value.
-5. Call the function implementation with the following arguments:
+
+4. Call the function implementation with the following arguments:
 
    - The current _locale_.
    - The resolved mapping of _options_.