diff --git a/users/sterni/mblog/maildir.lisp b/users/sterni/mblog/maildir.lisp
index 42f18c619..9acd2a401 100644
--- a/users/sterni/mblog/maildir.lisp
+++ b/users/sterni/mblog/maildir.lisp
@@ -4,12 +4,14 @@
 (in-package :maildir)
 (declaim (optimize (safety 3)))
 
+;; https://cr.yp.to/proto/maildir.html
+;; http://qmail.org/qmail-manual-html/man5/maildir.html
 (defun list (dir)
   "Returns a list of pathnames to messages in a maildir. The messages are
-  returned in no guaranteed order. Note that this function doesn't fully
-  implement the behavior prescribed by maildir(5): It only looks at `cur`
-  and `new` and won't clean up `tmp` nor move files from `new` to `cur`,
-  since it is strictly read-only."
+returned in no guaranteed order. Note that this function doesn't fully
+implement the behavior prescribed by maildir(5): It only looks at `cur`
+and `new` and won't clean up `tmp` nor move files from `new` to `cur`,
+since it is strictly read-only. In this, it follows mlist(1)."
   (flet ((subdir-contents (subdir)
            (directory
             (merge-pathnames