diff --git a/doc/28_ref_optional_semantics.qbk b/doc/28_ref_optional_semantics.qbk
index 8e2159f..007d8f8 100644
--- a/doc/28_ref_optional_semantics.qbk
+++ b/doc/28_ref_optional_semantics.qbk
@@ -1427,10 +1427,10 @@ struct hash<boost::optional<T&> > ;
 } // namespace std
 ``
 
-The specialization `hash<optional<T>>`` is enabled if and only if
-`hash<remove_­const_­t<T>> is enabled. When enabled, for an object `o`
+The specialization `hash<optional<T>>` is enabled if and only if
+`hash<remove_­const_­t<T>>` is enabled. When enabled, for an object `o`
 of type `optional<T>`, if `o.has_­value() == true`, then `hash<optional<T>>()(o)`
- evaluates to the same value as `hash<remove_­const_­t<T>>()(*o)``; otherwise it
+ evaluates to the same value as `hash<remove_­const_­t<T>>()(*o)`; otherwise it
 evaluates to an unspecified value.
 The member functions are not guaranteed to be `noexcept`.