diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
index a551e660ce..d6a31cf88c 100644
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -4555,6 +4555,7 @@ phutil_register_library_map(array(
       0 => 'PhabricatorProjectDAO',
       1 => 'PhabricatorFlaggableInterface',
       2 => 'PhabricatorPolicyInterface',
+      3 => 'PhabricatorSubscribableInterface',
     ),
     'PhabricatorProjectBoardController' => 'PhabricatorProjectController',
     'PhabricatorProjectBoardEditController' => 'PhabricatorProjectController',
diff --git a/src/applications/files/storage/PhabricatorFile.php b/src/applications/files/storage/PhabricatorFile.php
index d611f1b062..dc6ad6d1ad 100644
--- a/src/applications/files/storage/PhabricatorFile.php
+++ b/src/applications/files/storage/PhabricatorFile.php
@@ -933,6 +933,14 @@ final class PhabricatorFile extends PhabricatorFileDAO
     return ($this->authorPHID == $phid);
   }
 
+  public function shouldShowSubscribersProperty() {
+    return true;
+  }
+
+  public function shouldAllowSubscription($phid) {
+    return true;
+  }
+
 
 /* -(  PhabricatorTokenReceiverInterface  )---------------------------------- */
 
diff --git a/src/applications/harbormaster/storage/configuration/HarbormasterBuildPlan.php b/src/applications/harbormaster/storage/configuration/HarbormasterBuildPlan.php
index e3d505ce57..cffcda72ef 100644
--- a/src/applications/harbormaster/storage/configuration/HarbormasterBuildPlan.php
+++ b/src/applications/harbormaster/storage/configuration/HarbormasterBuildPlan.php
@@ -64,6 +64,14 @@ final class HarbormasterBuildPlan extends HarbormasterDAO
     return false;
   }
 
+  public function shouldShowSubscribersProperty() {
+    return true;
+  }
+
+  public function shouldAllowSubscription($phid) {
+    return true;
+  }
+
 
 /* -(  PhabricatorPolicyInterface  )----------------------------------------- */
 
diff --git a/src/applications/legalpad/storage/LegalpadDocument.php b/src/applications/legalpad/storage/LegalpadDocument.php
index 99208d81e1..6a3e4d18f9 100644
--- a/src/applications/legalpad/storage/LegalpadDocument.php
+++ b/src/applications/legalpad/storage/LegalpadDocument.php
@@ -91,13 +91,25 @@ final class LegalpadDocument extends LegalpadDAO
     return 'L'.$this->getID();
   }
 
-/* -(  PhabricatorSubscribableInterface Implementation  )-------------------- */
+
+/* -(  PhabricatorSubscribableInterface  )----------------------------------- */
+
 
   public function isAutomaticallySubscribed($phid) {
     return ($this->creatorPHID == $phid);
   }
 
-/* -(  PhabricatorPolicyInterface Implementation  )-------------------------- */
+  public function shouldShowSubscribersProperty() {
+    return true;
+  }
+
+  public function shouldAllowSubscription($phid) {
+    return true;
+  }
+
+
+/* -(  PhabricatorPolicyInterface  )----------------------------------------- */
+
 
   public function getCapabilities() {
     return array(
diff --git a/src/applications/macro/storage/PhabricatorFileImageMacro.php b/src/applications/macro/storage/PhabricatorFileImageMacro.php
index 0bd9e238d8..b8cdbf6a8f 100644
--- a/src/applications/macro/storage/PhabricatorFileImageMacro.php
+++ b/src/applications/macro/storage/PhabricatorFileImageMacro.php
@@ -79,6 +79,14 @@ final class PhabricatorFileImageMacro extends PhabricatorFileDAO
     return false;
   }
 
+  public function shouldShowSubscribersProperty() {
+    return true;
+  }
+
+  public function shouldAllowSubscription($phid) {
+    return true;
+  }
+
 
 /* -(  PhabricatorPolicyInterface  )----------------------------------------- */
 
diff --git a/src/applications/paste/storage/PhabricatorPaste.php b/src/applications/paste/storage/PhabricatorPaste.php
index 9e4c8ed265..4c3aee3236 100644
--- a/src/applications/paste/storage/PhabricatorPaste.php
+++ b/src/applications/paste/storage/PhabricatorPaste.php
@@ -87,6 +87,14 @@ final class PhabricatorPaste extends PhabricatorPasteDAO
     return ($this->authorPHID == $phid);
   }
 
+  public function shouldShowSubscribersProperty() {
+    return true;
+  }
+
+  public function shouldAllowSubscription($phid) {
+    return true;
+  }
+
 
 /* -(  PhabricatorTokenReceiverInterface  )---------------------------------- */
 
diff --git a/src/applications/pholio/storage/PholioMock.php b/src/applications/pholio/storage/PholioMock.php
index 740ac71a9e..3f48f31501 100644
--- a/src/applications/pholio/storage/PholioMock.php
+++ b/src/applications/pholio/storage/PholioMock.php
@@ -137,6 +137,14 @@ final class PholioMock extends PholioDAO
     return ($this->authorPHID == $phid);
   }
 
+  public function shouldShowSubscribersProperty() {
+    return true;
+  }
+
+  public function shouldAllowSubscription($phid) {
+    return true;
+  }
+
 
 /* -(  PhabricatorPolicyInterface Implementation  )-------------------------- */
 
diff --git a/src/applications/phriction/storage/PhrictionDocument.php b/src/applications/phriction/storage/PhrictionDocument.php
index 3e36a26a0b..6cb0658e4f 100644
--- a/src/applications/phriction/storage/PhrictionDocument.php
+++ b/src/applications/phriction/storage/PhrictionDocument.php
@@ -104,6 +104,10 @@ final class PhrictionDocument extends PhrictionDAO
     return $parts[1].'/';
   }
 
+
+/* -(  PhabricatorPolicyInterface  )----------------------------------------- */
+
+
   public function getCapabilities() {
     return array(
       PhabricatorPolicyCapability::CAN_VIEW,
@@ -133,12 +137,26 @@ final class PhrictionDocument extends PhrictionDAO
     return null;
   }
 
+
+/* -(  PhabricatorSubscribableInterface  )----------------------------------- */
+
+
   public function isAutomaticallySubscribed($phid) {
     return false;
   }
 
+  public function shouldShowSubscribersProperty() {
+    return true;
+  }
+
+  public function shouldAllowSubscription($phid) {
+    return true;
+  }
+
+
 /* -(  PhabricatorTokenReceiverInterface  )---------------------------------- */
 
+
   public function getUsersToNotifyOfTokenGiven() {
     return PhabricatorSubscribersQuery::loadSubscribersForPHID($this->phid);
   }
diff --git a/src/applications/ponder/storage/PonderAnswer.php b/src/applications/ponder/storage/PonderAnswer.php
index 3b6a8b9bd6..f21d22e055 100644
--- a/src/applications/ponder/storage/PonderAnswer.php
+++ b/src/applications/ponder/storage/PonderAnswer.php
@@ -188,5 +188,12 @@ final class PonderAnswer extends PonderDAO
     return ($phid == $this->getAuthorPHID());
   }
 
+  public function shouldShowSubscribersProperty() {
+    return true;
+  }
+
+  public function shouldAllowSubscription($phid) {
+    return true;
+  }
 
 }
diff --git a/src/applications/ponder/storage/PonderQuestion.php b/src/applications/ponder/storage/PonderQuestion.php
index 7309afde6a..ed21352ce6 100644
--- a/src/applications/ponder/storage/PonderQuestion.php
+++ b/src/applications/ponder/storage/PonderQuestion.php
@@ -170,10 +170,6 @@ final class PonderQuestion extends PonderDAO
     return $this->getPHID();
   }
 
-  public function isAutomaticallySubscribed($phid) {
-    return ($phid == $this->getAuthorPHID());
-  }
-
   public function save() {
     if (!$this->getMailKey()) {
       $this->setMailKey(Filesystem::readRandomCharacters(20));
@@ -181,6 +177,20 @@ final class PonderQuestion extends PonderDAO
     return parent::save();
   }
 
+  public function getOriginalTitle() {
+    // TODO: Make this actually save/return the original title.
+    return $this->getTitle();
+  }
+
+  public function getFullTitle() {
+    $id = $this->getID();
+    $title = $this->getTitle();
+    return "Q{$id}: {$title}";
+  }
+
+
+/* -(  PhabricatorPolicyInterface  )----------------------------------------- */
+
   public function getCapabilities() {
     return array(
       PhabricatorPolicyCapability::CAN_VIEW,
@@ -210,15 +220,20 @@ final class PonderQuestion extends PonderDAO
       'The user who asked a question can always view and edit it.');
   }
 
-  public function getOriginalTitle() {
-    // TODO: Make this actually save/return the original title.
-    return $this->getTitle();
+
+/* -(  PhabricatorSubscribableInterface  )----------------------------------- */
+
+
+  public function isAutomaticallySubscribed($phid) {
+    return ($phid == $this->getAuthorPHID());
   }
 
-  public function getFullTitle() {
-    $id = $this->getID();
-    $title = $this->getTitle();
-    return "Q{$id}: {$title}";
+  public function shouldShowSubscribersProperty() {
+    return true;
+  }
+
+  public function shouldAllowSubscription($phid) {
+    return true;
   }
 
 
diff --git a/src/applications/project/controller/PhabricatorProjectProfileController.php b/src/applications/project/controller/PhabricatorProjectProfileController.php
index cdfe73202a..f643e98c28 100644
--- a/src/applications/project/controller/PhabricatorProjectProfileController.php
+++ b/src/applications/project/controller/PhabricatorProjectProfileController.php
@@ -214,6 +214,7 @@ final class PhabricatorProjectProfileController
     }
     $view->addAction($action);
 
+
     $view->addAction(
       id(new PhabricatorActionView())
         ->setName(pht('View History'))
diff --git a/src/applications/project/storage/PhabricatorProject.php b/src/applications/project/storage/PhabricatorProject.php
index cdd24a15af..0377959401 100644
--- a/src/applications/project/storage/PhabricatorProject.php
+++ b/src/applications/project/storage/PhabricatorProject.php
@@ -3,7 +3,8 @@
 final class PhabricatorProject extends PhabricatorProjectDAO
   implements
     PhabricatorFlaggableInterface,
-    PhabricatorPolicyInterface {
+    PhabricatorPolicyInterface,
+    PhabricatorSubscribableInterface {
 
   protected $name;
   protected $status = PhabricatorProjectStatus::STATUS_ACTIVE;
@@ -15,7 +16,6 @@ final class PhabricatorProject extends PhabricatorProjectDAO
   protected $editPolicy;
   protected $joinPolicy;
 
-  private $subprojectsNeedUpdate;
   private $memberPHIDs = self::ATTACHABLE;
   private $sparseMembers = self::ATTACHABLE;
   private $profile = self::ATTACHABLE;
@@ -134,4 +134,21 @@ final class PhabricatorProject extends PhabricatorProjectDAO
     return 'projects/'.$slug;
   }
 
+
+/* -(  PhabricatorSubscribableInterface  )----------------------------------- */
+
+
+  public function isAutomaticallySubscribed($phid) {
+    return false;
+  }
+
+  public function shouldShowSubscribersProperty() {
+    return false;
+  }
+
+  public function shouldAllowSubscription($phid) {
+    return false;
+  }
+
+
 }
diff --git a/src/applications/slowvote/storage/PhabricatorSlowvotePoll.php b/src/applications/slowvote/storage/PhabricatorSlowvotePoll.php
index c306040b04..0bdb0555ca 100644
--- a/src/applications/slowvote/storage/PhabricatorSlowvotePoll.php
+++ b/src/applications/slowvote/storage/PhabricatorSlowvotePoll.php
@@ -125,6 +125,14 @@ final class PhabricatorSlowvotePoll extends PhabricatorSlowvoteDAO
     return ($phid == $this->getAuthorPHID());
   }
 
+  public function shouldShowSubscribersProperty() {
+    return true;
+  }
+
+  public function shouldAllowSubscription($phid) {
+    return true;
+  }
+
 
 /* -(  PhabricatorTokenReceiverInterface  )---------------------------------- */
 
diff --git a/src/applications/subscriptions/controller/PhabricatorSubscriptionsEditController.php b/src/applications/subscriptions/controller/PhabricatorSubscriptionsEditController.php
index d46fc37986..5dfd9b01f0 100644
--- a/src/applications/subscriptions/controller/PhabricatorSubscriptionsEditController.php
+++ b/src/applications/subscriptions/controller/PhabricatorSubscriptionsEditController.php
@@ -56,6 +56,13 @@ final class PhabricatorSubscriptionsEditController
         $handle->getURI());
     }
 
+    if (!$object->shouldAllowSubscription($user->getPHID())) {
+      return $this->buildErrorResponse(
+        pht('You Can Not Subscribe'),
+        pht('You can not subscribe to this object.'),
+        $handle->getURI());
+    }
+
     if ($object instanceof PhabricatorApplicationTransactionInterface) {
       if ($is_add) {
         $xaction_value = array(
diff --git a/src/applications/subscriptions/events/PhabricatorSubscriptionsUIEventListener.php b/src/applications/subscriptions/events/PhabricatorSubscriptionsUIEventListener.php
index aaf75766b0..0dd106efff 100644
--- a/src/applications/subscriptions/events/PhabricatorSubscriptionsUIEventListener.php
+++ b/src/applications/subscriptions/events/PhabricatorSubscriptionsUIEventListener.php
@@ -33,6 +33,11 @@ final class PhabricatorSubscriptionsUIEventListener
       return;
     }
 
+    if (!$object->shouldAllowSubscription($user->getPHID())) {
+      // This object doesn't allow the viewer to subscribe.
+      return;
+    }
+
     if ($object->isAutomaticallySubscribed($user->getPHID())) {
       $sub_action = id(new PhabricatorActionView())
         ->setWorkflow(true)
@@ -95,6 +100,12 @@ final class PhabricatorSubscriptionsUIEventListener
       // This object isn't subscribable.
       return;
     }
+
+    if (!$object->shouldShowSubscribersProperty()) {
+      // This object doesn't render subscribers in its property list.
+      return;
+    }
+
     $subscribers = PhabricatorSubscribersQuery::loadSubscribersForPHID(
       $object->getPHID());
     if ($subscribers) {
diff --git a/src/applications/subscriptions/interface/PhabricatorSubscribableInterface.php b/src/applications/subscriptions/interface/PhabricatorSubscribableInterface.php
index 8f87941ea5..95275e53bb 100644
--- a/src/applications/subscriptions/interface/PhabricatorSubscribableInterface.php
+++ b/src/applications/subscriptions/interface/PhabricatorSubscribableInterface.php
@@ -13,4 +13,43 @@ interface PhabricatorSubscribableInterface {
    */
   public function isAutomaticallySubscribed($phid);
 
+
+  /**
+   * Return `true` to indicate that "Subscribers:" should be shown when
+   * rendering property lists for this object, or `false` to omit the property.
+   *
+   * @return bool True to show the "Subscribers:" property.
+   */
+  public function shouldShowSubscribersProperty();
+
+
+  /**
+   * Return `true` to indicate that the "Subscribe" action should be shown and
+   * enabled when rendering action lists for this object, or `false` to omit
+   * the action.
+   *
+   * @param   phid  Viewing or acting user PHID.
+   * @return  bool  True to allow the user to subscribe.
+   */
+  public function shouldAllowSubscription($phid);
+
 }
+
+// TEMPLATE IMPLEMENTATION /////////////////////////////////////////////////////
+
+/* -(  PhabricatorSubscribableInterface  )----------------------------------- */
+/*
+
+  public function isAutomaticallySubscribed($phid) {
+    return false;
+  }
+
+  public function shouldShowSubscribersProperty() {
+    return true;
+  }
+
+  public function shouldAllowSubscription($phid) {
+    return true;
+  }
+
+*/