diff --git a/preserves-path.md b/preserves-path.md
index c3277a7..40cc197 100644
--- a/preserves-path.md
+++ b/preserves-path.md
@@ -72,7 +72,7 @@ Filters: narrow down a selection without moving
         le literal
         ge literal
 
-        re regex          ;; Matches strings and symbols by regular expression
+        re regex          ;; Matches strings and symbols by POSIX extended regular expression
         =r regex
 
         [pred]            ;; Applies predicate to each input; keeps inputs yielding truth