diff --git a/core/src/main/java/hudson/Util.java b/core/src/main/java/hudson/Util.java
index 72cda6e759..33b31bcd3f 100644
--- a/core/src/main/java/hudson/Util.java
+++ b/core/src/main/java/hudson/Util.java
@@ -719,9 +719,11 @@ public class Util {
      * Encode a single path component for use in an HTTP URL.
      * Escapes all non-ASCII, general unsafe (space and "#%<>[\]^`{|}~)
      * and HTTP special characters (/;:?) as specified in RFC1738.
-     * (so alphanumeric and !@$&*()-_=+',. are not encoded)
+     * Also escapes & for convenience.
+     * (so alphanumeric and !@$*()-_=+',. are not encoded)
      * Note that slash(/) is encoded, so the given string should be a
      * single path component used in constructing a URL.
+     * Do not use this method for encoding query parameters.
      * Method name inspired by PHP's rawurlencode.
      */
     public static String rawEncode(String s) {