diff --git a/src/package.lisp b/src/package.lisp
index b098f40..60e5c92 100644
--- a/src/package.lisp
+++ b/src/package.lisp
@@ -14,21 +14,34 @@
   (:import-from :alexandria
                 :make-keyword)
   (:export
-   ;; all html5 elements, e.g. div, nav, media, export in code except
-   ;; <time> and <map> conflicts with cl symbol, are defined and
-   ;; exported as |time|, |map|
+
+   ;;; all html5 elements, e.g. div, nav, media, export in code except
+   ;;; <time> and <map> conflicts with cl symbol, are defined and
+   ;;; exported as |time|, |map|
+   :html
+
+   ;;; user define elements
    :define-element
+   :*expand-user-element*
+
+   ;;; attribute accessing utilility
    :attrs
    :attrs-alist
    :make-attrs
    :copy-attrs
-   :html
+   :attr
+   :delete-attr
+
+   ;;; element slots
    :element-tag
    :element-attrs
    :element-children
    :user-element-expand-to
-   :*expand-user-element*
+
+   ;;; the h macro for avoiding import all builtin html element functions
    :h
+
+   ;;; escape utility
    :*escape-html*
    :escape-string
    :utf8-html-escape-char-p