diff --git a/externals/javelin b/externals/javelin
index 14e180d5d3..fb9944cff2 160000
--- a/externals/javelin
+++ b/externals/javelin
@@ -1 +1 @@
-Subproject commit 14e180d5d316d496886730cb6a41d1b36de16ec1
+Subproject commit fb9944cff2e2398ace77d2556f8b65edf88ebd58
diff --git a/src/__celerity_resource_map__.php b/src/__celerity_resource_map__.php
index 6667ce0c5c..112f78e245 100644
--- a/src/__celerity_resource_map__.php
+++ b/src/__celerity_resource_map__.php
@@ -154,7 +154,7 @@ celerity_register_resource_map(array(
   ),
   'aphront-typeahead-control-css' =>
   array(
-    'uri' => '/res/a05236a6/rsrc/css/aphront/typeahead.css',
+    'uri' => '/res/311e8830/rsrc/css/aphront/typeahead.css',
     'type' => 'css',
     'requires' =>
     array(
@@ -357,18 +357,12 @@ celerity_register_resource_map(array(
   ),
   'javelin-behavior-aphront-basic-tokenizer' =>
   array(
-    'uri' => '/res/69a085d3/rsrc/js/application/core/behavior-tokenizer.js',
+    'uri' => '/res/cf049052/rsrc/js/application/core/behavior-tokenizer.js',
     'type' => 'js',
     'requires' =>
     array(
       0 => 'javelin-behavior',
-      1 => 'javelin-typeahead',
-      2 => 'javelin-tokenizer',
-      3 => 'javelin-typeahead-preloaded-source',
-      4 => 'javelin-typeahead-ondemand-source',
-      5 => 'javelin-dom',
-      6 => 'javelin-stratcom',
-      7 => 'javelin-util',
+      1 => 'phabricator-prefab',
     ),
     'disk' => '/rsrc/js/application/core/behavior-tokenizer.js',
   ),
@@ -488,15 +482,13 @@ celerity_register_resource_map(array(
   ),
   'javelin-behavior-differential-add-reviewers-and-ccs' =>
   array(
-    'uri' => '/res/eb142486/rsrc/js/application/differential/behavior-add-reviewers-and-ccs.js',
+    'uri' => '/res/27be3f81/rsrc/js/application/differential/behavior-add-reviewers-and-ccs.js',
     'type' => 'js',
     'requires' =>
     array(
       0 => 'javelin-behavior',
       1 => 'javelin-dom',
-      2 => 'javelin-tokenizer',
-      3 => 'javelin-typeahead',
-      4 => 'javelin-typeahead-preloaded-source',
+      2 => 'phabricator-prefab',
     ),
     'disk' => '/rsrc/js/application/differential/behavior-add-reviewers-and-ccs.js',
   ),
@@ -739,15 +731,13 @@ celerity_register_resource_map(array(
   ),
   'javelin-behavior-maniphest-transaction-controls' =>
   array(
-    'uri' => '/res/33bd237a/rsrc/js/application/maniphest/behavior-transaction-controls.js',
+    'uri' => '/res/62465554/rsrc/js/application/maniphest/behavior-transaction-controls.js',
     'type' => 'js',
     'requires' =>
     array(
       0 => 'javelin-behavior',
       1 => 'javelin-dom',
-      2 => 'javelin-tokenizer',
-      3 => 'javelin-typeahead',
-      4 => 'javelin-typeahead-preloaded-source',
+      2 => 'phabricator-prefab',
     ),
     'disk' => '/rsrc/js/application/maniphest/behavior-transaction-controls.js',
   ),
@@ -1148,7 +1138,7 @@ celerity_register_resource_map(array(
   ),
   'javelin-tokenizer' =>
   array(
-    'uri' => '/res/aa86949c/rsrc/js/javelin/lib/control/tokenizer/Tokenizer.js',
+    'uri' => '/res/a8275d0d/rsrc/js/javelin/lib/control/tokenizer/Tokenizer.js',
     'type' => 'js',
     'requires' =>
     array(
@@ -1161,7 +1151,7 @@ celerity_register_resource_map(array(
   ),
   'javelin-typeahead' =>
   array(
-    'uri' => '/res/75d4b342/rsrc/js/javelin/lib/control/typeahead/Typeahead.js',
+    'uri' => '/res/2f694700/rsrc/js/javelin/lib/control/typeahead/Typeahead.js',
     'type' => 'js',
     'requires' =>
     array(
@@ -1224,7 +1214,7 @@ celerity_register_resource_map(array(
   ),
   'javelin-typeahead-source' =>
   array(
-    'uri' => '/res/e99c0c1d/rsrc/js/javelin/lib/control/typeahead/source/TypeaheadSource.js',
+    'uri' => '/res/ff342bbb/rsrc/js/javelin/lib/control/typeahead/source/TypeaheadSource.js',
     'type' => 'js',
     'requires' =>
     array(
@@ -1616,13 +1606,20 @@ celerity_register_resource_map(array(
   ),
   'phabricator-prefab' =>
   array(
-    'uri' => '/res/5784a112/rsrc/js/application/core/Prefab.js',
+    'uri' => '/res/956c8474/rsrc/js/application/core/Prefab.js',
     'type' => 'js',
     'requires' =>
     array(
       0 => 'javelin-install',
       1 => 'javelin-util',
       2 => 'javelin-dom',
+      3 => 'javelin-typeahead',
+      4 => 'javelin-tokenizer',
+      5 => 'javelin-typeahead-preloaded-source',
+      6 => 'javelin-typeahead-ondemand-source',
+      7 => 'javelin-dom',
+      8 => 'javelin-stratcom',
+      9 => 'javelin-util',
     ),
     'disk' => '/rsrc/js/application/core/Prefab.js',
   ),
@@ -1941,74 +1938,7 @@ celerity_register_resource_map(array(
       'uri' => '/res/pkg/09c86840/differential.pkg.css',
       'type' => 'css',
     ),
-    '0ed3e020' =>
-    array(
-      'name' => 'maniphest.pkg.js',
-      'symbols' =>
-      array(
-        0 => 'javelin-behavior-maniphest-batch-selector',
-        1 => 'javelin-behavior-maniphest-transaction-controls',
-        2 => 'javelin-behavior-maniphest-transaction-preview',
-        3 => 'javelin-behavior-maniphest-transaction-expand',
-      ),
-      'uri' => '/res/pkg/0ed3e020/maniphest.pkg.js',
-      'type' => 'js',
-    ),
-    '2b5d58e9' =>
-    array(
-      'name' => 'core.pkg.css',
-      'symbols' =>
-      array(
-        0 => 'phabricator-core-css',
-        1 => 'phabricator-core-buttons-css',
-        2 => 'phabricator-standard-page-view',
-        3 => 'aphront-dialog-view-css',
-        4 => 'aphront-form-view-css',
-        5 => 'aphront-panel-view-css',
-        6 => 'aphront-side-nav-view-css',
-        7 => 'aphront-table-view-css',
-        8 => 'aphront-crumbs-view-css',
-        9 => 'aphront-tokenizer-control-css',
-        10 => 'aphront-typeahead-control-css',
-        11 => 'aphront-list-filter-view-css',
-        12 => 'phabricator-directory-css',
-        13 => 'phabricator-jump-nav',
-        14 => 'phabricator-app-buttons-css',
-        15 => 'phabricator-remarkup-css',
-        16 => 'syntax-highlighting-css',
-        17 => 'aphront-pager-view-css',
-        18 => 'phabricator-transaction-view-css',
-      ),
-      'uri' => '/res/pkg/2b5d58e9/core.pkg.css',
-      'type' => 'css',
-    ),
-    '2e291441' =>
-    array(
-      'name' => 'differential.pkg.js',
-      'symbols' =>
-      array(
-        0 => 'phabricator-drag-and-drop-file-upload',
-        1 => 'phabricator-shaped-request',
-        2 => 'javelin-behavior-differential-feedback-preview',
-        3 => 'javelin-behavior-differential-edit-inline-comments',
-        4 => 'javelin-behavior-differential-populate',
-        5 => 'javelin-behavior-differential-show-more',
-        6 => 'javelin-behavior-differential-diff-radios',
-        7 => 'javelin-behavior-differential-accept-with-errors',
-        8 => 'javelin-behavior-differential-comment-jump',
-        9 => 'javelin-behavior-differential-add-reviewers-and-ccs',
-        10 => 'javelin-behavior-differential-keyboard-navigation',
-        11 => 'javelin-behavior-aphront-drag-and-drop',
-        12 => 'javelin-behavior-aphront-drag-and-drop-textarea',
-        13 => 'javelin-behavior-phabricator-object-selector',
-        14 => 'differential-inline-comment-editor',
-        15 => 'javelin-behavior-differential-dropdown-menus',
-        16 => 'javelin-behavior-buoyant',
-      ),
-      'uri' => '/res/pkg/2e291441/differential.pkg.js',
-      'type' => 'js',
-    ),
-    '3e7cc9b3' =>
+    '2af849fb' =>
     array(
       'name' => 'typeahead.pkg.js',
       'symbols' =>
@@ -2021,7 +1951,7 @@ celerity_register_resource_map(array(
         5 => 'javelin-tokenizer',
         6 => 'javelin-behavior-aphront-basic-tokenizer',
       ),
-      'uri' => '/res/pkg/3e7cc9b3/typeahead.pkg.js',
+      'uri' => '/res/pkg/2af849fb/typeahead.pkg.js',
       'type' => 'js',
     ),
     '4fbae2af' =>
@@ -2053,6 +1983,73 @@ celerity_register_resource_map(array(
       'uri' => '/res/pkg/61f9d480/diffusion.pkg.css',
       'type' => 'css',
     ),
+    '78e8854e' =>
+    array(
+      'name' => 'core.pkg.css',
+      'symbols' =>
+      array(
+        0 => 'phabricator-core-css',
+        1 => 'phabricator-core-buttons-css',
+        2 => 'phabricator-standard-page-view',
+        3 => 'aphront-dialog-view-css',
+        4 => 'aphront-form-view-css',
+        5 => 'aphront-panel-view-css',
+        6 => 'aphront-side-nav-view-css',
+        7 => 'aphront-table-view-css',
+        8 => 'aphront-crumbs-view-css',
+        9 => 'aphront-tokenizer-control-css',
+        10 => 'aphront-typeahead-control-css',
+        11 => 'aphront-list-filter-view-css',
+        12 => 'phabricator-directory-css',
+        13 => 'phabricator-jump-nav',
+        14 => 'phabricator-app-buttons-css',
+        15 => 'phabricator-remarkup-css',
+        16 => 'syntax-highlighting-css',
+        17 => 'aphront-pager-view-css',
+        18 => 'phabricator-transaction-view-css',
+      ),
+      'uri' => '/res/pkg/78e8854e/core.pkg.css',
+      'type' => 'css',
+    ),
+    '86fc0b0c' =>
+    array(
+      'name' => 'maniphest.pkg.js',
+      'symbols' =>
+      array(
+        0 => 'javelin-behavior-maniphest-batch-selector',
+        1 => 'javelin-behavior-maniphest-transaction-controls',
+        2 => 'javelin-behavior-maniphest-transaction-preview',
+        3 => 'javelin-behavior-maniphest-transaction-expand',
+      ),
+      'uri' => '/res/pkg/86fc0b0c/maniphest.pkg.js',
+      'type' => 'js',
+    ),
+    'e8b28c4a' =>
+    array(
+      'name' => 'differential.pkg.js',
+      'symbols' =>
+      array(
+        0 => 'phabricator-drag-and-drop-file-upload',
+        1 => 'phabricator-shaped-request',
+        2 => 'javelin-behavior-differential-feedback-preview',
+        3 => 'javelin-behavior-differential-edit-inline-comments',
+        4 => 'javelin-behavior-differential-populate',
+        5 => 'javelin-behavior-differential-show-more',
+        6 => 'javelin-behavior-differential-diff-radios',
+        7 => 'javelin-behavior-differential-accept-with-errors',
+        8 => 'javelin-behavior-differential-comment-jump',
+        9 => 'javelin-behavior-differential-add-reviewers-and-ccs',
+        10 => 'javelin-behavior-differential-keyboard-navigation',
+        11 => 'javelin-behavior-aphront-drag-and-drop',
+        12 => 'javelin-behavior-aphront-drag-and-drop-textarea',
+        13 => 'javelin-behavior-phabricator-object-selector',
+        14 => 'differential-inline-comment-editor',
+        15 => 'javelin-behavior-differential-dropdown-menus',
+        16 => 'javelin-behavior-buoyant',
+      ),
+      'uri' => '/res/pkg/e8b28c4a/differential.pkg.js',
+      'type' => 'js',
+    ),
     31583232 =>
     array(
       'name' => 'maniphest.pkg.css',
@@ -2092,20 +2089,20 @@ celerity_register_resource_map(array(
   'reverse' =>
   array(
     'aphront-attached-file-view-css' => '31583232',
-    'aphront-crumbs-view-css' => '2b5d58e9',
-    'aphront-dialog-view-css' => '2b5d58e9',
-    'aphront-form-view-css' => '2b5d58e9',
+    'aphront-crumbs-view-css' => '78e8854e',
+    'aphront-dialog-view-css' => '78e8854e',
+    'aphront-form-view-css' => '78e8854e',
     'aphront-headsup-action-list-view-css' => '09c86840',
-    'aphront-list-filter-view-css' => '2b5d58e9',
-    'aphront-pager-view-css' => '2b5d58e9',
-    'aphront-panel-view-css' => '2b5d58e9',
-    'aphront-side-nav-view-css' => '2b5d58e9',
-    'aphront-table-view-css' => '2b5d58e9',
-    'aphront-tokenizer-control-css' => '2b5d58e9',
-    'aphront-typeahead-control-css' => '2b5d58e9',
+    'aphront-list-filter-view-css' => '78e8854e',
+    'aphront-pager-view-css' => '78e8854e',
+    'aphront-panel-view-css' => '78e8854e',
+    'aphront-side-nav-view-css' => '78e8854e',
+    'aphront-table-view-css' => '78e8854e',
+    'aphront-tokenizer-control-css' => '78e8854e',
+    'aphront-typeahead-control-css' => '78e8854e',
     'differential-changeset-view-css' => '09c86840',
     'differential-core-view-css' => '09c86840',
-    'differential-inline-comment-editor' => '2e291441',
+    'differential-inline-comment-editor' => 'e8b28c4a',
     'differential-local-commits-view-css' => '09c86840',
     'differential-revision-add-comment-css' => '09c86840',
     'differential-revision-comment-css' => '09c86840',
@@ -2115,28 +2112,28 @@ celerity_register_resource_map(array(
     'differential-table-of-contents-css' => '09c86840',
     'diffusion-commit-view-css' => '61f9d480',
     'javelin-behavior' => '4fbae2af',
-    'javelin-behavior-aphront-basic-tokenizer' => '3e7cc9b3',
-    'javelin-behavior-aphront-drag-and-drop' => '2e291441',
-    'javelin-behavior-aphront-drag-and-drop-textarea' => '2e291441',
+    'javelin-behavior-aphront-basic-tokenizer' => '2af849fb',
+    'javelin-behavior-aphront-drag-and-drop' => 'e8b28c4a',
+    'javelin-behavior-aphront-drag-and-drop-textarea' => 'e8b28c4a',
     'javelin-behavior-aphront-form-disable-on-submit' => '95944588',
-    'javelin-behavior-buoyant' => '2e291441',
-    'javelin-behavior-differential-accept-with-errors' => '2e291441',
-    'javelin-behavior-differential-add-reviewers-and-ccs' => '2e291441',
-    'javelin-behavior-differential-comment-jump' => '2e291441',
-    'javelin-behavior-differential-diff-radios' => '2e291441',
-    'javelin-behavior-differential-dropdown-menus' => '2e291441',
-    'javelin-behavior-differential-edit-inline-comments' => '2e291441',
-    'javelin-behavior-differential-feedback-preview' => '2e291441',
-    'javelin-behavior-differential-keyboard-navigation' => '2e291441',
-    'javelin-behavior-differential-populate' => '2e291441',
-    'javelin-behavior-differential-show-more' => '2e291441',
-    'javelin-behavior-maniphest-batch-selector' => '0ed3e020',
-    'javelin-behavior-maniphest-transaction-controls' => '0ed3e020',
-    'javelin-behavior-maniphest-transaction-expand' => '0ed3e020',
-    'javelin-behavior-maniphest-transaction-preview' => '0ed3e020',
+    'javelin-behavior-buoyant' => 'e8b28c4a',
+    'javelin-behavior-differential-accept-with-errors' => 'e8b28c4a',
+    'javelin-behavior-differential-add-reviewers-and-ccs' => 'e8b28c4a',
+    'javelin-behavior-differential-comment-jump' => 'e8b28c4a',
+    'javelin-behavior-differential-diff-radios' => 'e8b28c4a',
+    'javelin-behavior-differential-dropdown-menus' => 'e8b28c4a',
+    'javelin-behavior-differential-edit-inline-comments' => 'e8b28c4a',
+    'javelin-behavior-differential-feedback-preview' => 'e8b28c4a',
+    'javelin-behavior-differential-keyboard-navigation' => 'e8b28c4a',
+    'javelin-behavior-differential-populate' => 'e8b28c4a',
+    'javelin-behavior-differential-show-more' => 'e8b28c4a',
+    'javelin-behavior-maniphest-batch-selector' => '86fc0b0c',
+    'javelin-behavior-maniphest-transaction-controls' => '86fc0b0c',
+    'javelin-behavior-maniphest-transaction-expand' => '86fc0b0c',
+    'javelin-behavior-maniphest-transaction-preview' => '86fc0b0c',
     'javelin-behavior-phabricator-autofocus' => '95944588',
     'javelin-behavior-phabricator-keyboard-shortcuts' => '95944588',
-    'javelin-behavior-phabricator-object-selector' => '2e291441',
+    'javelin-behavior-phabricator-object-selector' => 'e8b28c4a',
     'javelin-behavior-phabricator-watch-anchor' => '95944588',
     'javelin-behavior-refresh-csrf' => '95944588',
     'javelin-behavior-workflow' => '95944588',
@@ -2147,12 +2144,12 @@ celerity_register_resource_map(array(
     'javelin-mask' => '95944588',
     'javelin-request' => '4fbae2af',
     'javelin-stratcom' => '4fbae2af',
-    'javelin-tokenizer' => '3e7cc9b3',
-    'javelin-typeahead' => '3e7cc9b3',
-    'javelin-typeahead-normalizer' => '3e7cc9b3',
-    'javelin-typeahead-ondemand-source' => '3e7cc9b3',
-    'javelin-typeahead-preloaded-source' => '3e7cc9b3',
-    'javelin-typeahead-source' => '3e7cc9b3',
+    'javelin-tokenizer' => '2af849fb',
+    'javelin-typeahead' => '2af849fb',
+    'javelin-typeahead-normalizer' => '2af849fb',
+    'javelin-typeahead-ondemand-source' => '2af849fb',
+    'javelin-typeahead-preloaded-source' => '2af849fb',
+    'javelin-typeahead-source' => '2af849fb',
     'javelin-uri' => '4fbae2af',
     'javelin-util' => '4fbae2af',
     'javelin-vector' => '4fbae2af',
@@ -2160,23 +2157,23 @@ celerity_register_resource_map(array(
     'maniphest-task-detail-css' => '31583232',
     'maniphest-task-summary-css' => '31583232',
     'maniphest-transaction-detail-css' => '31583232',
-    'phabricator-app-buttons-css' => '2b5d58e9',
+    'phabricator-app-buttons-css' => '78e8854e',
     'phabricator-content-source-view-css' => '09c86840',
-    'phabricator-core-buttons-css' => '2b5d58e9',
-    'phabricator-core-css' => '2b5d58e9',
-    'phabricator-directory-css' => '2b5d58e9',
-    'phabricator-drag-and-drop-file-upload' => '2e291441',
+    'phabricator-core-buttons-css' => '78e8854e',
+    'phabricator-core-css' => '78e8854e',
+    'phabricator-directory-css' => '78e8854e',
+    'phabricator-drag-and-drop-file-upload' => 'e8b28c4a',
     'phabricator-dropdown-menu' => '95944588',
-    'phabricator-jump-nav' => '2b5d58e9',
+    'phabricator-jump-nav' => '78e8854e',
     'phabricator-keyboard-shortcut' => '95944588',
     'phabricator-keyboard-shortcut-manager' => '95944588',
     'phabricator-menu-item' => '95944588',
     'phabricator-object-selector-css' => '09c86840',
     'phabricator-paste-file-upload' => '95944588',
-    'phabricator-remarkup-css' => '2b5d58e9',
-    'phabricator-shaped-request' => '2e291441',
-    'phabricator-standard-page-view' => '2b5d58e9',
-    'phabricator-transaction-view-css' => '2b5d58e9',
-    'syntax-highlighting-css' => '2b5d58e9',
+    'phabricator-remarkup-css' => '78e8854e',
+    'phabricator-shaped-request' => 'e8b28c4a',
+    'phabricator-standard-page-view' => '78e8854e',
+    'phabricator-transaction-view-css' => '78e8854e',
+    'syntax-highlighting-css' => '78e8854e',
   ),
 ));
diff --git a/src/applications/differential/view/addcomment/DifferentialAddCommentView.php b/src/applications/differential/view/addcomment/DifferentialAddCommentView.php
index 1527e81ee2..5d8c57a581 100644
--- a/src/applications/differential/view/addcomment/DifferentialAddCommentView.php
+++ b/src/applications/differential/view/addcomment/DifferentialAddCommentView.php
@@ -128,12 +128,14 @@ final class DifferentialAddCommentView extends AphrontView {
             'src' => '/typeahead/common/users/',
             'row' => 'add-reviewers',
             'ondemand' => PhabricatorEnv::getEnvConfig('tokenizer.ondemand'),
+            'placeholder' => 'Type a user name...',
           ),
           'add-ccs-tokenizer' => array(
             'actions' => array('add_ccs' => 1),
             'src' => '/typeahead/common/mailable/',
             'row' => 'add-ccs',
             'ondemand' => PhabricatorEnv::getEnvConfig('tokenizer.ondemand'),
+            'placeholder' => 'Type a user or mailing list...',
           ),
         ),
         'select' => 'comment-action',
diff --git a/src/applications/maniphest/controller/taskdetail/ManiphestTaskDetailController.php b/src/applications/maniphest/controller/taskdetail/ManiphestTaskDetailController.php
index 7341064208..86b2188ffa 100644
--- a/src/applications/maniphest/controller/taskdetail/ManiphestTaskDetailController.php
+++ b/src/applications/maniphest/controller/taskdetail/ManiphestTaskDetailController.php
@@ -450,6 +450,7 @@ final class ManiphestTaskDetailController extends ManiphestController {
           'id'       => 'projects-tokenizer',
           'src'      => '/typeahead/common/projects/',
           'ondemand' => PhabricatorEnv::getEnvConfig('tokenizer.ondemand'),
+          'placeholder' => 'Type a project name...',
         ),
         ManiphestTransactionType::TYPE_OWNER => array(
           'id'       => 'assign-tokenizer',
@@ -457,11 +458,13 @@ final class ManiphestTaskDetailController extends ManiphestController {
           'value'    => $default_claim,
           'limit'    => 1,
           'ondemand' => PhabricatorEnv::getEnvConfig('tokenizer.ondemand'),
+          'placeholder' => 'Type a user name...',
         ),
         ManiphestTransactionType::TYPE_CCS => array(
           'id'       => 'cc-tokenizer',
           'src'      => '/typeahead/common/mailable/',
           'ondemand' => PhabricatorEnv::getEnvConfig('tokenizer.ondemand'),
+          'placeholder' => 'Type a user or mailing list...',
         ),
       ),
     ));
diff --git a/src/applications/maniphest/controller/taskedit/ManiphestTaskEditController.php b/src/applications/maniphest/controller/taskedit/ManiphestTaskEditController.php
index efe62ce180..c07e0a7820 100644
--- a/src/applications/maniphest/controller/taskedit/ManiphestTaskEditController.php
+++ b/src/applications/maniphest/controller/taskedit/ManiphestTaskEditController.php
@@ -390,6 +390,7 @@ final class ManiphestTaskEditController extends ManiphestController {
           ->setLabel('Assigned To')
           ->setName('assigned_to')
           ->setValue($assigned_value)
+          ->setUser($user)
           ->setDatasource('/typeahead/common/users/')
           ->setLimit(1))
       ->appendChild(
@@ -397,6 +398,7 @@ final class ManiphestTaskEditController extends ManiphestController {
           ->setLabel('CC')
           ->setName('cc')
           ->setValue($cc_value)
+          ->setUser($user)
           ->setDatasource('/typeahead/common/mailable/'))
       ->appendChild(
         id(new AphrontFormSelectControl())
diff --git a/src/view/form/control/tokenizer/AphrontFormTokenizerControl.php b/src/view/form/control/tokenizer/AphrontFormTokenizerControl.php
index bef0b2827c..70d0ca7913 100644
--- a/src/view/form/control/tokenizer/AphrontFormTokenizerControl.php
+++ b/src/view/form/control/tokenizer/AphrontFormTokenizerControl.php
@@ -22,6 +22,7 @@ class AphrontFormTokenizerControl extends AphrontFormControl {
   private $disableBehavior;
   private $limit;
   private $user;
+  private $placeholder;
 
   public function setDatasource($datasource) {
     $this->datasource = $datasource;
@@ -47,6 +48,11 @@ class AphrontFormTokenizerControl extends AphrontFormControl {
     return $this;
   }
 
+  public function setPlaceholder($placeholder) {
+    $this->placeholder = $placeholder;
+    return $this;
+  }
+
   protected function renderInput() {
     $name = $this->getName();
     $values = nonempty($this->getValue(), array());
@@ -57,6 +63,11 @@ class AphrontFormTokenizerControl extends AphrontFormControl {
       $id = celerity_generate_unique_node_id();
     }
 
+    $placeholder = null;
+    if (!$this->placeholder) {
+      $placeholder = $this->getDefaultPlaceholder();
+    }
+
     $template = new AphrontTokenizerTemplateView();
     $template->setName($name);
     $template->setID($id);
@@ -69,17 +80,43 @@ class AphrontFormTokenizerControl extends AphrontFormControl {
 
     if (!$this->disableBehavior) {
       Javelin::initBehavior('aphront-basic-tokenizer', array(
-        'id'        => $id,
-        'src'       => $this->datasource,
-        'value'     => $values,
-        'limit'     => $this->limit,
-        'ondemand'  => PhabricatorEnv::getEnvConfig('tokenizer.ondemand'),
-        'username'  => $username,
+        'id'          => $id,
+        'src'         => $this->datasource,
+        'value'       => $values,
+        'limit'       => $this->limit,
+        'ondemand'    => PhabricatorEnv::getEnvConfig('tokenizer.ondemand'),
+        'username'    => $username,
+        'placeholder' => $placeholder,
       ));
     }
 
     return $template->render();
   }
 
+  private function getDefaultPlaceholder() {
+    $datasource = $this->datasource;
+
+    $matches = null;
+    if (!preg_match('@^/typeahead/common/(.*)/$@', $datasource, $matches)) {
+      return null;
+    }
+
+    $request = $matches[1];
+
+    $map = array(
+      'users'           => 'Type a user name...',
+      'searchowner'     => 'Type a user name...',
+      'accounts'        => 'Type a user name...',
+      'mailable'        => 'Type a user or mailing list...',
+      'searchproject'   => 'Type a project name...',
+      'projects'        => 'Type a project name...',
+      'repositories'    => 'Type a repository name...',
+      'packages'        => 'Type a package name...',
+      'arcanistproject' => 'Type an arc project name...',
+    );
+
+    return idx($map, $request);
+  }
+
 
 }
diff --git a/webroot/rsrc/css/aphront/typeahead.css b/webroot/rsrc/css/aphront/typeahead.css
index b3a7b18142..0cbd5d14c8 100644
--- a/webroot/rsrc/css/aphront/typeahead.css
+++ b/webroot/rsrc/css/aphront/typeahead.css
@@ -42,3 +42,7 @@ table.jx-typeahead input {
   font-size: 13px;
   padding: 2px;
 }
+
+input.jx-typeahead-placeholder {
+  color: #888888;
+}
diff --git a/webroot/rsrc/js/application/core/Prefab.js b/webroot/rsrc/js/application/core/Prefab.js
index fedbb35843..9f2fc008cc 100644
--- a/webroot/rsrc/js/application/core/Prefab.js
+++ b/webroot/rsrc/js/application/core/Prefab.js
@@ -3,6 +3,13 @@
  * @requires javelin-install
  *           javelin-util
  *           javelin-dom
+ *           javelin-typeahead
+ *           javelin-tokenizer
+ *           javelin-typeahead-preloaded-source
+ *           javelin-typeahead-ondemand-source
+ *           javelin-dom
+ *           javelin-stratcom
+ *           javelin-util
  * @javelin
  */
 
@@ -22,6 +29,107 @@ JX.install('Prefab', {
       }
       select.value = select.value || JX.keys(map)[0];
       return select;
+    },
+
+    /**
+     * Build a Phabricator tokenizer out of a configuration with application
+     * sorting, datasource and placeholder rules.
+     *
+     *   - `id` Root tokenizer ID.
+     *   - `src` Datasource URI.
+     *   - `ondemand` Optional, use an ondemand source.
+     *   - `value` Optional, initial value.
+     *   - `limit` Optional, token limit.
+     *   - `placeholder` Optional, placeholder text.
+     *   - `username` Optional, username to sort first (i.e., viewer).
+     *
+     */
+    buildTokenizer : function(config) {
+      var root = JX.$(config.id);
+
+      var datasource;
+      if (config.ondemand) {
+        datasource = new JX.TypeaheadOnDemandSource(config.src);
+      } else {
+        datasource = new JX.TypeaheadPreloadedSource(config.src);
+      }
+
+      // Sort results so that the viewing user always comes up first; after
+      // that, prefer unixname matches to realname matches.
+
+      var sort_handler = function(value, list, cmp) {
+        var priority_hits = {};
+        var self_hits     = {};
+
+        var tokens = this.tokenize(value);
+
+        for (var ii = 0; ii < list.length; ii++) {
+          var item = list[ii];
+          if (!item.priority) {
+            continue;
+          }
+
+          if (config.username && item.priority == config.username) {
+            self_hits[item.id] = true;
+          }
+
+          for (var jj = 0; jj < tokens.length; jj++) {
+            if (item.priority.substr(0, tokens[jj].length) == tokens[jj]) {
+              priority_hits[item.id] = true;
+            }
+          }
+        }
+
+        list.sort(function(u, v) {
+          if (self_hits[u.id] != self_hits[v.id]) {
+            return self_hits[v.id] ? 1 : -1;
+          }
+
+          if (priority_hits[u.id] != priority_hits[v.id]) {
+            return priority_hits[v.id] ? 1 : -1;
+          }
+
+          return cmp(u, v);
+        });
+      };
+
+      datasource.setSortHandler(JX.bind(datasource, sort_handler));
+      datasource.setTransformer(
+        function(object) {
+          return {
+            name: object[0],
+            display: object[0],
+            uri: object[1],
+            id: object[2],
+            priority: object[3]
+          };
+        });
+
+      var typeahead = new JX.Typeahead(
+        root,
+        JX.DOM.find(root, 'input', 'tokenizer-input'));
+      typeahead.setDatasource(datasource);
+
+      var tokenizer = new JX.Tokenizer(root);
+      tokenizer.setTypeahead(typeahead);
+
+      if (config.placeholder) {
+        tokenizer.setPlaceholder(config.placeholder);
+      }
+
+      if (config.limit) {
+        tokenizer.setLimit(config.limit);
+      }
+
+      if (config.value) {
+        tokenizer.setInitialValue(config.value);
+      }
+
+      JX.Stratcom.addData(root, {'tokenizer' : tokenizer});
+
+      return {
+        tokenizer: tokenizer
+      };
     }
   }
 
diff --git a/webroot/rsrc/js/application/core/behavior-tokenizer.js b/webroot/rsrc/js/application/core/behavior-tokenizer.js
index fe02ac4a67..ec7bc4a7cd 100644
--- a/webroot/rsrc/js/application/core/behavior-tokenizer.js
+++ b/webroot/rsrc/js/application/core/behavior-tokenizer.js
@@ -1,94 +1,9 @@
 /**
  * @provides javelin-behavior-aphront-basic-tokenizer
  * @requires javelin-behavior
- *           javelin-typeahead
- *           javelin-tokenizer
- *           javelin-typeahead-preloaded-source
- *           javelin-typeahead-ondemand-source
- *           javelin-dom
- *           javelin-stratcom
- *           javelin-util
+ *           phabricator-prefab
  */
 
 JX.behavior('aphront-basic-tokenizer', function(config) {
-  var root = JX.$(config.id);
-
-  var datasource;
-  if (config.ondemand) {
-    datasource = new JX.TypeaheadOnDemandSource(config.src);
-  } else {
-    datasource = new JX.TypeaheadPreloadedSource(config.src);
-  }
-
-  // Sort results so that the viewing user always comes up first; after that,
-  // prefer unixname matches to realname matches.
-
-  var sort_handler = function(value, list, cmp) {
-    var priority_hits = {};
-    var self_hits     = {};
-
-    var tokens = this.tokenize(value);
-
-    for (var ii = 0; ii < list.length; ii++) {
-      var item = list[ii];
-      if (!item.priority) {
-        continue;
-      }
-
-      if (config.username && item.priority == config.username) {
-        self_hits[item.id] = true;
-      }
-
-      for (var jj = 0; jj < tokens.length; jj++) {
-        if (item.priority.substr(0, tokens[jj].length) == tokens[jj]) {
-          priority_hits[item.id] = true;
-        }
-      }
-    }
-
-    list.sort(function(u, v) {
-      if (self_hits[u.id] != self_hits[v.id]) {
-        return self_hits[v.id] ? 1 : -1;
-      }
-
-      if (priority_hits[u.id] != priority_hits[v.id]) {
-        return priority_hits[v.id] ? 1 : -1;
-      }
-
-      return cmp(u, v);
-    });
-  };
-
-  datasource.setSortHandler(JX.bind(datasource, sort_handler));
-  datasource.setTransformer(
-    function(object) {
-      return {
-        name : object[0],
-        display : object[0],
-        uri : object[1],
-        id : object[2],
-        priority : object[3]
-      };
-    });
-
-  var typeahead = new JX.Typeahead(
-    root,
-    JX.DOM.find(root, 'input', 'tokenizer-input'));
-  typeahead.setDatasource(datasource);
-
-  var tokenizer = new JX.Tokenizer(root);
-  tokenizer.setTypeahead(typeahead);
-
-  if (config.limit) {
-    tokenizer.setLimit(config.limit);
-  }
-
-  if (config.value) {
-    tokenizer.setInitialValue(config.value);
-  }
-
-  JX.Stratcom.addData(root, {'tokenizer' : tokenizer});
-
-  tokenizer.start();
-
+  JX.Prefab.buildTokenizer(config).tokenizer.start();
 });
diff --git a/webroot/rsrc/js/application/differential/behavior-add-reviewers-and-ccs.js b/webroot/rsrc/js/application/differential/behavior-add-reviewers-and-ccs.js
index d9d6187d06..6c2d72b6b5 100644
--- a/webroot/rsrc/js/application/differential/behavior-add-reviewers-and-ccs.js
+++ b/webroot/rsrc/js/application/differential/behavior-add-reviewers-and-ccs.js
@@ -2,42 +2,22 @@
  * @provides javelin-behavior-differential-add-reviewers-and-ccs
  * @requires javelin-behavior
  *           javelin-dom
- *           javelin-tokenizer
- *           javelin-typeahead
- *           javelin-typeahead-preloaded-source
+ *           phabricator-prefab
  */
 
 JX.behavior('differential-add-reviewers-and-ccs', function(config) {
 
-  function buildTokenizer(id, props) {
-    var root = JX.$(id);
-
-    var datasource;
-    if (props.ondemand) {
-      datasource = new JX.TypeaheadOnDemandSource(props.src);
-    } else {
-      datasource = new JX.TypeaheadPreloadedSource(props.src);
-    }
-
-    var typeahead = new JX.Typeahead(root);
-    typeahead.setDatasource(datasource);
-
-    var tokenizer = new JX.Tokenizer(root);
-    tokenizer.setTypeahead(typeahead);
-
-    JX.Stratcom.addData(root, {'tokenizer' : tokenizer});
-
-    tokenizer.start();
-
-    return tokenizer;
-  }
-
   var dynamic = {};
   for (var k in config.dynamic) {
-    props = config.dynamic[k];
+    var props = config.dynamic[k];
+    props.id = k;
+
+    var tokenizer = JX.Prefab.buildTokenizer(props).tokenizer;
+    tokenizer.start();
+
     dynamic[k] = {
       row : JX.$(props.row),
-      tokenizer : buildTokenizer(k, props),
+      tokenizer : tokenizer,
       actions : props.actions
     };
   }
diff --git a/webroot/rsrc/js/application/maniphest/behavior-transaction-controls.js b/webroot/rsrc/js/application/maniphest/behavior-transaction-controls.js
index 40f90a5849..b532f9b0b6 100644
--- a/webroot/rsrc/js/application/maniphest/behavior-transaction-controls.js
+++ b/webroot/rsrc/js/application/maniphest/behavior-transaction-controls.js
@@ -2,9 +2,7 @@
  * @provides javelin-behavior-maniphest-transaction-controls
  * @requires javelin-behavior
  *           javelin-dom
- *           javelin-tokenizer
- *           javelin-typeahead
- *           javelin-typeahead-preloaded-source
+ *           phabricator-prefab
  */
 
 JX.behavior('maniphest-transaction-controls', function(config) {
@@ -13,35 +11,8 @@ JX.behavior('maniphest-transaction-controls', function(config) {
 
   for (var k in config.tokenizers) {
     var tconfig = config.tokenizers[k];
-    var root = JX.$(tconfig.id);
-
-    var datasource;
-    if (tconfig.ondemand) {
-      datasource = new JX.TypeaheadOnDemandSource(tconfig.src);
-    } else {
-      datasource = new JX.TypeaheadPreloadedSource(tconfig.src);
-    }
-
-    var typeahead = new JX.Typeahead(root);
-    typeahead.setDatasource(datasource);
-
-    var tokenizer = new JX.Tokenizer(root);
-    tokenizer.setTypeahead(typeahead);
-
-    if (tconfig.limit) {
-      tokenizer.setLimit(tconfig.limit);
-    }
-
-    tokenizer.start();
-
-
-    if (tconfig.value) {
-      for (var jj in tconfig.value) {
-        tokenizer.addToken(jj, tconfig.value[jj]);
-      }
-    }
-
-    tokenizers[k] = tokenizer;
+    tokenizers[k] = JX.Prefab.buildTokenizer(tconfig).tokenizer;
+    tokenizers[k].start()
   }
 
   JX.DOM.listen(