diff --git a/src/applications/differential/customfield/DifferentialRevertPlanField.php b/src/applications/differential/customfield/DifferentialRevertPlanField.php
index 2b35612e2b..e39c373a9d 100644
--- a/src/applications/differential/customfield/DifferentialRevertPlanField.php
+++ b/src/applications/differential/customfield/DifferentialRevertPlanField.php
@@ -126,4 +126,9 @@ final class DifferentialRevertPlanField
       $xaction->getNewValue());
   }
 
+  public function getApplicationTransactionRemarkupBlocks(
+    PhabricatorApplicationTransaction $xaction) {
+    return array($xaction->getNewValue());
+  }
+
 }
diff --git a/src/applications/differential/customfield/DifferentialSummaryField.php b/src/applications/differential/customfield/DifferentialSummaryField.php
index 8b7b64e1b7..aa5437b55c 100644
--- a/src/applications/differential/customfield/DifferentialSummaryField.php
+++ b/src/applications/differential/customfield/DifferentialSummaryField.php
@@ -118,4 +118,9 @@ final class DifferentialSummaryField
       $this->getViewer());
   }
 
+  public function getApplicationTransactionRemarkupBlocks(
+    PhabricatorApplicationTransaction $xaction) {
+    return array($xaction->getNewValue());
+  }
+
 }
diff --git a/src/applications/differential/customfield/DifferentialTestPlanField.php b/src/applications/differential/customfield/DifferentialTestPlanField.php
index 91620f0e53..ad36b001c8 100644
--- a/src/applications/differential/customfield/DifferentialTestPlanField.php
+++ b/src/applications/differential/customfield/DifferentialTestPlanField.php
@@ -133,4 +133,9 @@ final class DifferentialTestPlanField
       $this->getViewer());
   }
 
+  public function getApplicationTransactionRemarkupBlocks(
+    PhabricatorApplicationTransaction $xaction) {
+    return array($xaction->getNewValue());
+  }
+
 }
diff --git a/src/applications/differential/editor/DifferentialTransactionEditor.php b/src/applications/differential/editor/DifferentialTransactionEditor.php
index 6d30484f91..5fc15e71de 100644
--- a/src/applications/differential/editor/DifferentialTransactionEditor.php
+++ b/src/applications/differential/editor/DifferentialTransactionEditor.php
@@ -706,10 +706,11 @@ final class DifferentialTransactionEditor
   }
 
   protected function sortTransactions(array $xactions) {
+    $xactions = parent::sortTransactions();
+
     $head = array();
     $tail = array();
 
-    // Move bare comments to the end, so the actions precede them.
     foreach ($xactions as $xaction) {
       $type = $xaction->getTransactionType();
       if ($type == DifferentialTransaction::TYPE_INLINE) {
@@ -823,6 +824,78 @@ final class DifferentialTransactionEditor
     return parent::extractFilePHIDsFromCustomTransaction($object, $xaction);
   }
 
+  protected function expandCustomRemarkupBlockTransactions(
+    PhabricatorLiskDAO $object,
+    array $xactions,
+    $blocks,
+    PhutilMarkupEngine $engine) {
+
+
+    $flat_blocks = array_mergev($blocks);
+    $huge_block = implode("\n\n", $flat_blocks);
+
+    $task_map = array();
+    $task_refs = id(new ManiphestCustomFieldStatusParser())
+      ->parseCorpus($huge_block);
+    foreach ($task_refs as $match) {
+      foreach ($match['monograms'] as $monogram) {
+        $task_id = (int)trim($monogram, 'tT');
+        $task_map[$task_id] = true;
+      }
+    }
+
+    $rev_map = array();
+    $rev_refs = id(new DifferentialCustomFieldDependsOnParser())
+      ->parseCorpus($huge_block);
+    foreach ($rev_refs as $match) {
+      foreach ($match['monograms'] as $monogram) {
+        $rev_id = (int)trim($monogram, 'dD');
+        $rev_map[$rev_id] = true;
+      }
+    }
+
+    $edges = array();
+
+    if ($task_map) {
+      $tasks = id(new ManiphestTaskQuery())
+        ->setViewer($this->getActor())
+        ->withIDs(array_keys($task_map))
+        ->execute();
+
+      if ($tasks) {
+        $edge_related = PhabricatorEdgeConfig::TYPE_DREV_HAS_RELATED_TASK;
+        $edges[$edge_related] = mpull($tasks, 'getPHID', 'getPHID');
+      }
+    }
+
+    if ($rev_map) {
+      $revs = id(new DifferentialRevisionQuery())
+        ->setViewer($this->getActor())
+        ->withIDs(array_keys($rev_map))
+        ->execute();
+      $rev_phids = mpull($revs, 'getPHID', 'getPHID');
+
+      // NOTE: Skip any write attempts if a user cleverly implies a revision
+      // depends upon itself.
+      unset($rev_phids[$object->getPHID()]);
+
+      if ($revs) {
+        $edge_depends = PhabricatorEdgeConfig::TYPE_DREV_DEPENDS_ON_DREV;
+        $edges[$edge_depends] = $rev_phids;
+      }
+    }
+
+    $result = array();
+    foreach ($edges as $type => $specs) {
+      $result[] = id(new DifferentialTransaction())
+        ->setTransactionType(PhabricatorTransactions::TYPE_EDGE)
+        ->setMetadataValue('edge:type', $type)
+        ->setNewValue(array('+' => $specs));
+    }
+
+    return $result;
+  }
+
   private function renderInlineCommentsForMail(
     PhabricatorLiskDAO $object,
     array $inlines) {
diff --git a/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php b/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
index 587e0e283d..387fe6b57c 100644
--- a/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
+++ b/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
@@ -435,16 +435,15 @@ abstract class PhabricatorApplicationTransactionEditor
 
     $actor = $this->requireActor();
 
-    $this->loadSubscribers($object);
-
-    $xactions = $this->applyImplicitCC($object, $xactions);
-
-    $mention_xaction = $this->buildMentionTransaction($object, $xactions);
-    if ($mention_xaction) {
-      $xactions[] = $mention_xaction;
+    // NOTE: Some transaction expansion requires that the edited object be
+    // attached.
+    foreach ($xactions as $xaction) {
+      $xaction->attachObject($object);
+      $xaction->attachViewer($actor);
     }
 
     $xactions = $this->expandTransactions($object, $xactions);
+    $xactions = $this->expandSupportTransactions($object, $xactions);
     $xactions = $this->combineTransactions($xactions);
 
     foreach ($xactions as $xaction) {
@@ -802,18 +801,14 @@ abstract class PhabricatorApplicationTransactionEditor
 
   private function buildMentionTransaction(
     PhabricatorLiskDAO $object,
-    array $xactions) {
+    array $xactions,
+    array $blocks) {
 
     if (!($object instanceof PhabricatorSubscribableInterface)) {
       return null;
     }
 
-    $texts = array();
-    foreach ($xactions as $xaction) {
-      $texts[] = $this->getRemarkupBlocksFromTransaction($xaction);
-    }
-    $texts = array_mergev($texts);
-
+    $texts = array_mergev($blocks);
     $phids = PhabricatorMarkupEngine::extractPHIDsFromMentions($texts);
 
     $this->mentionedPHIDs = $phids;
@@ -845,11 +840,7 @@ abstract class PhabricatorApplicationTransactionEditor
 
   protected function getRemarkupBlocksFromTransaction(
     PhabricatorApplicationTransaction $transaction) {
-    $texts = array();
-    if ($transaction->getComment()) {
-      $texts[] = $transaction->getComment()->getContent();
-    }
-    return $texts;
+    return $transaction->getRemarkupBlocks();
   }
 
   protected function mergeTransactions(
@@ -899,6 +890,64 @@ abstract class PhabricatorApplicationTransactionEditor
     return array($xaction);
   }
 
+
+  private function expandSupportTransactions(
+    PhabricatorLiskDAO $object,
+    array $xactions) {
+    $this->loadSubscribers($object);
+
+    $xactions = $this->applyImplicitCC($object, $xactions);
+
+    $blocks = array();
+    foreach ($xactions as $key => $xaction) {
+      $blocks[$key] = $this->getRemarkupBlocksFromTransaction($xaction);
+    }
+
+    $mention_xaction = $this->buildMentionTransaction(
+      $object,
+      $xactions,
+      $blocks);
+    if ($mention_xaction) {
+      $xactions[] = $mention_xaction;
+    }
+
+    // TODO: For now, this is just a placeholder.
+    $engine = PhabricatorMarkupEngine::getEngine('extract');
+
+    $block_xactions = $this->expandRemarkupBlockTransactions(
+      $object,
+      $xactions,
+      $blocks,
+      $engine);
+
+    foreach ($block_xactions as $xaction) {
+      $xactions[] = $xaction;
+    }
+
+    return $xactions;
+  }
+
+  private function expandRemarkupBlockTransactions(
+    PhabricatorLiskDAO $object,
+    array $xactions,
+    $blocks,
+    PhutilMarkupEngine $engine) {
+    return $this->expandCustomRemarkupBlockTransactions(
+      $object,
+      $xactions,
+      $blocks,
+      $engine);
+  }
+
+  protected function expandCustomRemarkupBlockTransactions(
+    PhabricatorLiskDAO $object,
+    array $xactions,
+    $blocks,
+    PhutilMarkupEngine $engine) {
+    return array();
+  }
+
+
   /**
    * Attempt to combine similar transactions into a smaller number of total
    * transactions. For example, two transactions which edit the title of an
@@ -1830,7 +1879,6 @@ abstract class PhabricatorApplicationTransactionEditor
     }
     $blocks = array_mergev($blocks);
 
-
     $phids = array();
     if ($blocks) {
       $phids[] = PhabricatorMarkupEngine::extractFilePHIDsFromEmbeddedFiles(
diff --git a/src/applications/transactions/storage/PhabricatorApplicationTransaction.php b/src/applications/transactions/storage/PhabricatorApplicationTransaction.php
index 1d777a3872..151f346f06 100644
--- a/src/applications/transactions/storage/PhabricatorApplicationTransaction.php
+++ b/src/applications/transactions/storage/PhabricatorApplicationTransaction.php
@@ -138,6 +138,30 @@ abstract class PhabricatorApplicationTransaction
     return $this->assertAttached($this->object);
   }
 
+  public function getRemarkupBlocks() {
+    $blocks = array();
+
+    switch ($this->getTransactionType()) {
+      case PhabricatorTransactions::TYPE_CUSTOMFIELD:
+        $field = $this->getTransactionCustomField();
+        if ($field) {
+          $custom_blocks = $field->getApplicationTransactionRemarkupBlocks(
+            $this);
+          foreach ($custom_blocks as $custom_block) {
+            $blocks[] = $custom_block;
+          }
+        }
+        break;
+    }
+
+    if ($this->getComment()) {
+      $blocks[] = $this->getComment()->getContent();
+    }
+
+    return $blocks;
+  }
+
+
 /* -(  Rendering  )---------------------------------------------------------- */
 
   public function setRenderingTarget($rendering_target) {
diff --git a/src/infrastructure/customfield/field/PhabricatorCustomField.php b/src/infrastructure/customfield/field/PhabricatorCustomField.php
index 9048e003bb..162eda8b29 100644
--- a/src/infrastructure/customfield/field/PhabricatorCustomField.php
+++ b/src/infrastructure/customfield/field/PhabricatorCustomField.php
@@ -848,6 +848,18 @@ abstract class PhabricatorCustomField {
   }
 
 
+  /**
+   * @task appxaction
+   */
+  public function getApplicationTransactionRemarkupBlocks(
+    PhabricatorApplicationTransaction $xaction) {
+    if ($this->proxy) {
+      return $this->proxy->getApplicationTransactionRemarkupBlocks($xaction);
+    }
+    return array();
+  }
+
+
   /**
    * @task appxaction
    */
diff --git a/src/infrastructure/markup/PhabricatorMarkupEngine.php b/src/infrastructure/markup/PhabricatorMarkupEngine.php
index 5fa43f8f66..bb1ef76d09 100644
--- a/src/infrastructure/markup/PhabricatorMarkupEngine.php
+++ b/src/infrastructure/markup/PhabricatorMarkupEngine.php
@@ -379,6 +379,12 @@ final class PhabricatorMarkupEngine {
   //    $engine->setConfig('diviner.renderer', new DivinerDefaultRenderer());
         $engine->setConfig('header.generate-toc', true);
         break;
+      case 'extract':
+        // Engine used for reference/edge extraction. Turn off anything which
+        // is slow and doesn't change reference extraction.
+        $engine = self::newMarkupEngine(array());
+        $engine->setConfig('pygments.enabled', false);
+        break;
       default:
         throw new Exception("Unknown engine ruleset: {$ruleset}!");
     }