diff --git a/src/modes/pair.rs b/src/modes/pair.rs
index 1e1f295..310f34d 100644
--- a/src/modes/pair.rs
+++ b/src/modes/pair.rs
@@ -9,7 +9,8 @@ impl Pair {
     if a Pair cannot be constructed out of the two cards.
 
     NOTE: By construction, if the Pair includes a Joker, that Joker will be the
-    first member of the pair.
+    first member of the pair.  In other words, Pair::1 will always be a valid
+    playing card.
      */
     fn new(c1: Card, c2: Card) -> Option<Pair> {
         // Order the cards.  This means if xor(c1 is joker, c2 is joker) c1 will