diff --git a/syndicate/mc/preserve.md b/syndicate/mc/preserve.md
index 2b784a1..7b8344b 100644
--- a/syndicate/mc/preserve.md
+++ b/syndicate/mc/preserve.md
@@ -294,7 +294,8 @@ Any `Value` may be preceded by whitespace.
                      String / ByteString / Symbol
 
 Each `Record` is its label-`Value` followed by a parenthesised
-grouping of its field-`Value`s.
+grouping of its field-`Value`s. Whitespace is not permitted between
+the label and the open-parenthesis.
 
             Record = Value "(" *Value ws ")"