diff --git a/config/punctuation/default.conf b/config/punctuation/default.conf
index f177c2ac..9b5e1622 100644
--- a/config/punctuation/default.conf
+++ b/config/punctuation/default.conf
@@ -65,6 +65,10 @@ _:===:line
 .*[\s*|'|"]:-\)[\s*|'|"].*:===:smile
 .*[\s*|'|"]:\)[\s*|'|"].*:===:smile
 .*[\s*|'|"]->[\s*|'|"].*:===:arrow right
+# example for arrow left
+#(?:[ |^])(<-)(?:[ ,.!?$]):===:arrow left
+# or
+#([ |^])<-([ ,.!?$]):===:arrow left\2
 .*[\s*|'|"]<-[\s*|'|"].*:===:arrow left
 .*[\s*|'|"][O|o][O|o][\s*|'|"].*:===:WTF?
 .*[\s*|'|"]\^\^[\s*|'|"].*:===:enjoy smile