diff --git a/multiple-cursors-core.el b/multiple-cursors-core.el
index ce65729..233eff5 100644
--- a/multiple-cursors-core.el
+++ b/multiple-cursors-core.el
@@ -250,14 +250,14 @@ cursor with updated info."
                 (overlays-in (point-min) (point-max)))))
 
 (defun mc/execute-this-command-for-all-cursors ()
-  "Used with post-command-hook to execute supported commands for
-all cursors. It also checks a list of explicitly unsupported
-commands that is prevented even for the original cursor, to
-inform about the lack of support.
+  "Used with post-command-hook to execute supported commands for all cursors.
 
-Commands that are neither supported nor explicitly unsupported
-is executed normally for point, but skipped for the fake
-cursors."
+It uses two lists of commands to know what to do: the run-once
+list and the run-for-all list. If a command is in neither of these lists,
+it will prompt for the proper action and then save that preference.
+
+Some commands are so unsupported that they are even prevented for
+the original cursor, to inform about the lack of support."
   (if (eq 1 (mc/num-cursors)) ;; no fake cursors? disable mc-mode
       (multiple-cursors-mode 0)
     (let ((original-command (or (command-remapping this-original-command)
@@ -306,6 +306,7 @@ multiple cursors editing.")
   (define-key mc/keymap (kbd "<return>") 'multiple-cursors-mode))
 
 (defun mc--all-equal (entries)
+  "Are all these entries equal?"
   (let ((first (car entries))
         (all-equal t))
     (while (and all-equal entries)
@@ -314,12 +315,16 @@ multiple cursors editing.")
     all-equal))
 
 (defun mc--kill-ring-entries ()
+  "Return the latest kill-ring entry for each cursor.
+The entries are returned in the order they are found in the buffer."
   (let (entries)
     (mc/for-each-cursor-ordered
      (setq entries (cons (car (overlay-get cursor 'kill-ring)) entries)))
     (reverse entries)))
 
 (defun mc--maybe-set-killed-rectangle ()
+  "Add the latest kill-ring entry for each cursor to killed-rectangle.
+So you can paste it in later with `yank-rectangle'."
   (let ((entries (mc--kill-ring-entries)))
     (unless (mc--all-equal entries)
       (setq killed-rectangle entries))))
@@ -382,6 +387,7 @@ from being executed if in multiple-cursors-mode."
 for running commands with multiple cursors.")
 
 (defun mc/save-lists ()
+  "Saves preferences for running commands with multiple cursors to `mc/list-file'"
   (with-temp-file mc/list-file
     (emacs-lisp-mode)
     (insert ";; This file is automatically generated by the multiple-cursors extension.")
diff --git a/multiple-cursors.el b/multiple-cursors.el
index 98b593c..31c3bb9 100644
--- a/multiple-cursors.el
+++ b/multiple-cursors.el
@@ -125,7 +125,6 @@
 ;;
 ;;; Code:
 
-(require 'multiple-cursors-core)
 (require 'mc-edit-lines)
 (require 'mc-cycle-cursors)
 (require 'mc-mark-more)
diff --git a/rectangular-region-mode.el b/rectangular-region-mode.el
index d0c3c8d..d6c9b73 100644
--- a/rectangular-region-mode.el
+++ b/rectangular-region-mode.el
@@ -39,6 +39,7 @@
 (define-key rectangular-region-mode-map (kbd "<return>") 'rrm/switch-to-multiple-cursors)
 
 (defun rrm/keyboard-quit ()
+  "Exit rectangular-region-mode."
   (interactive)
   (rectangular-region-mode 0)
   (rrm/remove-rectangular-region-overlays)
@@ -47,12 +48,17 @@
 ;; Bind this to a key (for instance H-SPC) to start rectangular-region-mode
 ;;;###autoload
 (defun set-rectangular-region-anchor ()
+  "Anchors the rectangular region at point.
+
+Think of this one as `set-mark' except you're marking a rectangular region. It is
+an exceedingly quick way of adding multiple cursors to multiple lines."
   (interactive)
   (set-marker rrm/anchor (point))
   (push-mark (point))
   (rectangular-region-mode 1))
 
 (defun rrm/remove-rectangular-region-overlays ()
+  "Remove all rectangular-region overlays."
   (mc/remove-fake-cursors)
   (mapc #'(lambda (o)
             (when (eq (overlay-get o 'type) 'additional-region)
@@ -60,6 +66,7 @@
         (overlays-in (point-min) (point-max))))
 
 (defun rrm/repaint ()
+  "Start from the anchor and draw a rectangle between it and point."
   (rrm/remove-rectangular-region-overlays)
   (let* ((annoying-arrows-mode nil)
          (point-column (current-column))
@@ -83,6 +90,7 @@
            (mc/create-fake-cursor-at-point)))))))
 
 (defun rrm/switch-to-multiple-cursors (&rest forms)
+  "Switch from rectangular-region-mode to multiple-cursors-mode."
   (interactive)
   (rectangular-region-mode 0)
   (multiple-cursors-mode 1))