diff --git a/actions/sandbox.php b/actions/sandbox.php
index d1ef4c86b2..ddbca40b2d 100644
--- a/actions/sandbox.php
+++ b/actions/sandbox.php
@@ -40,7 +40,6 @@ if (!defined('STATUSNET')) {
  * @license  http://www.fsf.org/licensing/licenses/agpl.html AGPLv3
  * @link     http://status.net/
  */
-
 class SandboxAction extends ProfileFormAction
 {
     /**
@@ -50,7 +49,6 @@ class SandboxAction extends ProfileFormAction
      *
      * @return boolean success flag
      */
-
     function prepare($args)
     {
         if (!parent::prepare($args)) {
@@ -62,6 +60,7 @@ class SandboxAction extends ProfileFormAction
         assert(!empty($cur)); // checked by parent
 
         if (!$cur->hasRight(Right::SANDBOXUSER)) {
+            // TRANS: Client error displayed trying to sandbox users on a site where the feature is not enabled.
             $this->clientError(_('You cannot sandbox users on this site.'));
             return false;
         }
@@ -69,6 +68,7 @@ class SandboxAction extends ProfileFormAction
         assert(!empty($this->profile)); // checked by parent
 
         if ($this->profile->isSandboxed()) {
+            // TRANS: Client error displayed trying to sandbox an already sandboxed user.
             $this->clientError(_('User is already sandboxed.'));
             return false;
         }
@@ -81,7 +81,6 @@ class SandboxAction extends ProfileFormAction
      *
      * @return void
      */
-
     function handlePost()
     {
         $this->profile->sandbox();
diff --git a/actions/sessionsadminpanel.php b/actions/sessionsadminpanel.php
index e9bd1719f2..0d1ead1021 100644
--- a/actions/sessionsadminpanel.php
+++ b/actions/sessionsadminpanel.php
@@ -40,7 +40,6 @@ if (!defined('STATUSNET')) {
  * @license  http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
  * @link     http://status.net/
  */
-
 class SessionsadminpanelAction extends AdminPanelAction
 {
     /**
@@ -48,10 +47,10 @@ class SessionsadminpanelAction extends AdminPanelAction
      *
      * @return string page title
      */
-
     function title()
     {
-        return _('Sessions');
+        // TRANS: Title for the sessions administration panel.
+        return _m('TITLE','Sessions');
     }
 
     /**
@@ -59,9 +58,9 @@ class SessionsadminpanelAction extends AdminPanelAction
      *
      * @return string instructions
      */
-
     function getInstructions()
     {
+        // TRANS: Instructions for the sessions administration panel.
         return _('Session settings for this StatusNet site');
     }
 
@@ -70,7 +69,6 @@ class SessionsadminpanelAction extends AdminPanelAction
      *
      * @return void
      */
-
     function showForm()
     {
         $form = new SessionsAdminPanelForm($this);
@@ -83,7 +81,6 @@ class SessionsadminpanelAction extends AdminPanelAction
      *
      * @return void
      */
-
     function saveSettings()
     {
         static $booleans = array('sessions' => array('handle', 'debug'));
@@ -123,6 +120,7 @@ class SessionsadminpanelAction extends AdminPanelAction
     }
 }
 
+// @todo FIXME: Class documentation missing.
 class SessionsAdminPanelForm extends AdminForm
 {
     /**
@@ -130,7 +128,6 @@ class SessionsAdminPanelForm extends AdminForm
      *
      * @return int ID of the form
      */
-
     function id()
     {
         return 'sessionsadminpanel';
@@ -141,7 +138,6 @@ class SessionsAdminPanelForm extends AdminForm
      *
      * @return string class of the form
      */
-
     function formClass()
     {
         return 'form_settings';
@@ -152,7 +148,6 @@ class SessionsAdminPanelForm extends AdminForm
      *
      * @return string URL of the action
      */
-
     function action()
     {
         return common_local_url('sessionsadminpanel');
@@ -163,24 +158,31 @@ class SessionsAdminPanelForm extends AdminForm
      *
      * @return void
      */
-
     function formData()
     {
         $this->out->elementStart('fieldset', array('id' => 'settings_user_sessions'));
-        $this->out->element('legend', null, _('Sessions'));
+        // TRANS: Fieldset legend on the sessions administration panel.
+        $this->out->element('legend', null, _m('LEGEND','Sessions'));
 
         $this->out->elementStart('ul', 'form_data');
 
         $this->li();
+        // TRANS: Checkbox title on the sessions administration panel.
+        // TRANS: Indicates if StatusNet should handle session administration.
         $this->out->checkbox('handle', _('Handle sessions'),
                               (bool) $this->value('handle', 'sessions'),
-                              _('Whether to handle sessions ourselves.'));
+                              // TRANS: Checkbox title on the sessions administration panel.
+                              // TRANS: Indicates if StatusNet should handle session administration.
+                              _('Handle sessions ourselves.'));
         $this->unli();
 
         $this->li();
+        // TRANS: Checkbox label on the sessions administration panel.
+        // TRANS: Indicates if StatusNet should write session debugging output.
         $this->out->checkbox('debug', _('Session debugging'),
                               (bool) $this->value('debug', 'sessions'),
-                              _('Turn on debugging output for sessions.'));
+                              // TRANS: Checkbox title on the sessions administration panel.
+                              _('Enable debugging output for sessions.'));
         $this->unli();
 
         $this->out->elementEnd('ul');
@@ -193,9 +195,14 @@ class SessionsAdminPanelForm extends AdminForm
      *
      * @return void
      */
-
     function formActions()
     {
-        $this->out->submit('submit', _('Save'), 'submit', null, _('Save site settings'));
+        $this->out->submit('submit',
+                           // TRANS: Submit button text on the sessions administration panel.
+                           _m('BUTTON','Save'),
+                           'submit',
+                           null,
+                           // TRANS: Title for submit button on the sessions administration panel.
+                           _('Save session settings'));
     }
 }
diff --git a/actions/showapplication.php b/actions/showapplication.php
index 02a4dc1517..38e6f1953e 100644
--- a/actions/showapplication.php
+++ b/actions/showapplication.php
@@ -75,11 +75,13 @@ class ShowApplicationAction extends OwnerDesignAction
         $this->owner        = User::staticGet($this->application->owner);
 
         if (!common_logged_in()) {
+            // TRANS: Client error displayed trying to display an OAuth application while not logged in.
             $this->clientError(_('You must be logged in to view an application.'));
             return false;
         }
 
         if (empty($this->application)) {
+            // TRANS: Client error displayed trying to display a non-existing OAuth application.
             $this->clientError(_('No such application.'), 404);
             return false;
         }
@@ -87,6 +89,7 @@ class ShowApplicationAction extends OwnerDesignAction
         $cur = common_current_user();
 
         if ($cur->id != $this->owner->id) {
+            // TRANS: Client error displayed trying to display an OAuth application for which the logged in user is not the owner.
             $this->clientError(_('You are not the owner of this application.'), 401);
             return false;
         }
@@ -148,6 +151,7 @@ class ShowApplicationAction extends OwnerDesignAction
         $consumer = $this->application->getConsumer();
 
         $this->elementStart('div', 'entity_profile vcard');
+        // TRANS: Header on the OAuth application page.
         $this->element('h2', null, _('Application profile'));
         if (!empty($this->application->icon)) {
             $this->element('img', array('src' => $this->application->icon,
@@ -176,7 +180,12 @@ class ShowApplicationAction extends OwnerDesignAction
         $userCnt = $appUsers->count();
 
         $this->raw(sprintf(
-            _('Created by %1$s - %2$s access by default - %3$d users'),
+            // TRANS: Information output on an OAuth application page.
+            // TRANS: %1$s is the application creator, %2$s is "read-only" or "read-write",
+            // TRANS: %3$d is the number of users using the OAuth application.
+            _m('Created by %1$s - %2$s access by default - %3$d user',
+               'Created by %1$s - %2$s access by default - %3$d users',
+               $userCnt),
               $profile->getBestName(),
               $defaultAccess,
               $userCnt
@@ -186,13 +195,15 @@ class ShowApplicationAction extends OwnerDesignAction
         $this->elementEnd('div');
 
         $this->elementStart('div', 'entity_actions');
+        // TRANS: Header on the OAuth application page.
         $this->element('h2', null, _('Application actions'));
         $this->elementStart('ul');
         $this->elementStart('li', 'entity_edit');
         $this->element('a',
                        array('href' => common_local_url('editapplication',
                                                         array('id' => $this->application->id))),
-                       'Edit');
+                       // TRANS: Link text to edit application on the OAuth application page.
+                       _m('EDITAPP','Edit'));
         $this->elementEnd('li');
 
         $this->elementStart('li', 'entity_reset_keysecret');
@@ -209,6 +220,8 @@ class ShowApplicationAction extends OwnerDesignAction
                                       'id' => 'reset',
                                       'name' => 'reset',
                                       'class' => 'submit',
+                                      // TRANS: Button text on the OAuth application page.
+                                      // TRANS: Resets the OAuth consumer key and secret.
                                       'value' => _('Reset key & secret'),
                                       'onClick' => 'return confirmReset()'));
         $this->elementEnd('fieldset');
@@ -225,7 +238,8 @@ class ShowApplicationAction extends OwnerDesignAction
 
         $this->elementStart('fieldset');
         $this->hidden('token', common_session_token());
-        $this->submit('delete', _('Delete'));
+        // TRANS: Submit button text the OAuth application page to delete an application.
+        $this->submit('delete', _m('BUTTON','Delete'));
         $this->elementEnd('fieldset');
         $this->elementEnd('form');
         $this->elementEnd('li');
@@ -234,6 +248,7 @@ class ShowApplicationAction extends OwnerDesignAction
         $this->elementEnd('div');
 
         $this->elementStart('div', 'entity_data');
+        // TRANS: Header on the OAuth application page.
         $this->element('h2', null, _('Application info'));
         $this->element('div',
                        'entity_consumer_key',
@@ -252,7 +267,8 @@ class ShowApplicationAction extends OwnerDesignAction
         $this->element('div', 'entity_authorize_url', common_local_url('ApiOauthAuthorize'));
 
         $this->element('p', 'note',
-            _('Note: We support HMAC-SHA1 signatures. We do not support the plaintext signature method.'));
+            // TRANS: Note on the OAuth application page about signature support.
+            _('Note: HMAC-SHA1 signatures are supported. The plaintext signature method is not supported.'));
         $this->elementEnd('div');
 
         $this->elementStart('p', array('id' => 'application_action'));
@@ -272,6 +288,7 @@ class ShowApplicationAction extends OwnerDesignAction
     {
         parent::showScripts();
 
+        // TRANS: Text in confirmation dialog to reset consumer key and secret for an OAuth application.
         $msg = _('Are you sure you want to reset your consumer key and secret?');
 
         $js  = 'function confirmReset() { ';
diff --git a/actions/showgroup.php b/actions/showgroup.php
index aa1f620880..d77fbeed71 100644
--- a/actions/showgroup.php
+++ b/actions/showgroup.php
@@ -324,6 +324,8 @@ class ShowgroupAction extends GroupDesignAction
         $this->element('h2', null, _('Statistics'));
 
         $this->elementStart('dl');
+
+        // TRANS: Label for group creation date.
         $this->element('dt', null, _m('LABEL','Created'));
         $this->element('dd', 'entity_created', date('j M Y',
                                                  strtotime($this->group->created)));
@@ -382,8 +384,8 @@ class GroupAdminSection extends ProfileSection
 
     function title()
     {
-        // TRANS: Header for list of group administrators on a group page (h2).
-        return _('Admins');
+        // TRANS: Title for list of group administrators on a group page.
+        return _m('TITLE','Admins');
     }
 
     function divId()