diff --git a/README.rst b/README.rst
index 0e2d5da..21bd4f3 100644
--- a/README.rst
+++ b/README.rst
@@ -19,7 +19,8 @@ You have to have voice in the channel (+v) to send commands to the ptgbot.
 Commands follow the following format::
 
   #TRACK [now|next] TOPIC
-  #TRACK [color] CSS_COLOR_SPECIFIER
+  #TRACK color CSS_COLOR_SPECIFIER
+  #TRACK book SLOT_REFERENCE
 
 Please note that:
 
diff --git a/html/ptg.html b/html/ptg.html
index 7041fba..d58e6b8 100644
--- a/html/ptg.html
+++ b/html/ptg.html
@@ -111,7 +111,11 @@
      {{#each @root.additional as |schedule room|}}
      <tr><td>{{room}}</td>
       {{#each (lookup @root.slots day) as |time|}}
+      {{#if (lookup schedule time.name)}}
       <td><span class="label label-primary {{lookup schedule time.name}}">{{lookup schedule time.name}}</td>
+      {{else}}
+      <td><small><i>{{room}}-{{time.name}}</i></small></td>
+      {{/if}}
       {{/each}}
      </tr>
      {{/each}}
@@ -119,6 +123,7 @@
     </div>
    {{/each}}
    </div>
+   <small><i>Use #TRACK book SLOTREF to book one of those empty slots</i></small></td>
   </div>
 </div>
 <p class="text-muted">Content on this page is being driven by room operators through the openstackptg bot on the #openstack-ptg IRC channel. It was last refreshed on {{timestamp}}.</p>
diff --git a/ptgbot/bot.py b/ptgbot/bot.py
index 6ae7a34..b085e36 100644
--- a/ptgbot/bot.py
+++ b/ptgbot/bot.py
@@ -129,17 +129,24 @@ class PTGBot(irc.bot.SingleServerIRCBot):
                 return
 
             adverb = words[1].lower()
-            session = str.join(' ', words[2:])
+            params = str.join(' ', words[2:])
             if adverb == 'now':
-                self.data.add_now(track, session)
+                self.data.add_now(track, params)
             elif adverb == 'next':
-                self.data.add_next(track, session)
+                self.data.add_next(track, params)
             elif adverb == 'clean':
                 self.data.clean_tracks([track])
             elif adverb == 'color':
-                self.data.add_color(track, session)
+                self.data.add_color(track, params)
             elif adverb == 'location':
-                self.data.add_location(track, session)
+                self.data.add_location(track, params)
+            elif adverb == 'book':
+                room, timeslot = params.split('-')
+                if self.data.is_slot_valid_and_empty(room, timeslot):
+                    self.data.book(track, room, timeslot)
+                else:
+                    self.send(chan, "%s: invalid slot reference '%s'" %
+                              (nick, params))
             else:
                 self.send(chan, "%s: unknown directive '%s'" % (nick, adverb))
                 self.usage(chan)
diff --git a/ptgbot/db.py b/ptgbot/db.py
index bb3bf7f..944df6b 100644
--- a/ptgbot/db.py
+++ b/ptgbot/db.py
@@ -104,6 +104,16 @@ class PTGDataBase():
                 del self.data['next'][track]
         self.save()
 
+    def is_slot_valid_and_empty(self, room, timeslot):
+        try:
+            return not self.data['additional'][room][timeslot]
+        except KeyError:
+            return False
+
+    def book(self, track, room, timeslot):
+        self.data['additional'][room][timeslot] = track
+        self.save()
+
     def wipe(self):
         self.data = self.BASE
         self.save()