diff --git a/actions/joingroup.php b/actions/joingroup.php
index f87e5dae29..7beaf4f64a 100644
--- a/actions/joingroup.php
+++ b/actions/joingroup.php
@@ -43,7 +43,6 @@ if (!defined('STATUSNET') && !defined('LACONICA')) {
  * @license  http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
  * @link     http://status.net/
  */
-
 class JoingroupAction extends Action
 {
     var $group = null;
@@ -51,12 +50,12 @@ class JoingroupAction extends Action
     /**
      * Prepare to run
      */
-
     function prepare($args)
     {
         parent::prepare($args);
 
         if (!common_logged_in()) {
+            // TRANS: Client error displayed when trying to join a group while not logged in.
             $this->clientError(_('You must be logged in to join a group.'));
             return false;
         }
@@ -79,17 +78,20 @@ class JoingroupAction extends Action
             $local = Local_group::staticGet('nickname', $nickname);
 
             if (!$local) {
+                // TRANS: Client error displayed when trying to join a non-local group.
                 $this->clientError(_('No such group.'), 404);
                 return false;
             }
 
             $this->group = User_group::staticGet('id', $local->group_id);
         } else {
+            // TRANS: Client error displayed when trying to join a group without providing a group name or group ID.
             $this->clientError(_('No nickname or ID.'), 404);
             return false;
         }
 
         if (!$this->group) {
+            // TRANS: Client error displayed when trying to join a non-existing group.
             $this->clientError(_('No such group.'), 404);
             return false;
         }
@@ -97,11 +99,13 @@ class JoingroupAction extends Action
         $cur = common_current_user();
 
         if ($cur->isMember($this->group)) {
+            // TRANS: Client error displayed when trying to join a group while already a member.
             $this->clientError(_('You are already a member of that group.'), 403);
             return false;
         }
 
         if (Group_block::isBlocked($this->group, $cur->getProfile())) {
+            // TRANS: Client error displayed when trying to join a group while being blocked form joining it.
             $this->clientError(_('You have been blocked from that group by the admin.'), 403);
             return false;
         }
@@ -118,7 +122,6 @@ class JoingroupAction extends Action
      *
      * @return void
      */
-
     function handle($args)
     {
         parent::handle($args);
@@ -131,6 +134,8 @@ class JoingroupAction extends Action
                 Event::handle('EndJoinGroup', array($this->group, $cur));
             }
         } catch (Exception $e) {
+            // TRANS: Server error displayed when joining a group failed in the database.
+            // TRANS: %1$s is the joining user's nickname, $2$s is the group nickname for which the join failed.
             $this->serverError(sprintf(_('Could not join user %1$s to group %2$s.'),
                                        $cur->nickname, $this->group->nickname));
         }
@@ -138,7 +143,8 @@ class JoingroupAction extends Action
         if ($this->boolean('ajax')) {
             $this->startHTML('text/xml;charset=utf-8');
             $this->elementStart('head');
-            $this->element('title', null, sprintf(_('%1$s joined group %2$s'),
+            // TRANS: Title for join group page after joining.
+            $this->element('title', null, sprintf(_m('TITLE','%1$s joined group %2$s'),
                                                   $cur->nickname,
                                                   $this->group->nickname));
             $this->elementEnd('head');
@@ -153,4 +159,4 @@ class JoingroupAction extends Action
                             303);
         }
     }
-}
\ No newline at end of file
+}
diff --git a/actions/leavegroup.php b/actions/leavegroup.php
index 329b5aafe1..f5d1ccd08c 100644
--- a/actions/leavegroup.php
+++ b/actions/leavegroup.php
@@ -43,7 +43,6 @@ if (!defined('STATUSNET') && !defined('LACONICA')) {
  * @license  http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
  * @link     http://status.net/
  */
-
 class LeavegroupAction extends Action
 {
     var $group = null;
@@ -51,12 +50,12 @@ class LeavegroupAction extends Action
     /**
      * Prepare to run
      */
-
     function prepare($args)
     {
         parent::prepare($args);
 
         if (!common_logged_in()) {
+            // TRANS: Client error displayed when trying to leave a group while not logged in.
             $this->clientError(_('You must be logged in to leave a group.'));
             return false;
         }
@@ -79,17 +78,20 @@ class LeavegroupAction extends Action
             $local = Local_group::staticGet('nickname', $nickname);
 
             if (!$local) {
+                // TRANS: Client error displayed when trying to leave a non-local group.
                 $this->clientError(_('No such group.'), 404);
                 return false;
             }
 
             $this->group = User_group::staticGet('id', $local->group_id);
         } else {
+            // TRANS: Client error displayed when trying to leave a group without providing a group name or group ID.
             $this->clientError(_('No nickname or ID.'), 404);
             return false;
         }
 
         if (!$this->group) {
+            // TRANS: Client error displayed when trying to leave a non-existing group.
             $this->clientError(_('No such group.'), 404);
             return false;
         }
@@ -97,6 +99,7 @@ class LeavegroupAction extends Action
         $cur = common_current_user();
 
         if (!$cur->isMember($this->group)) {
+            // TRANS: Client error displayed when trying to join a group while already a member.
             $this->clientError(_('You are not a member of that group.'), 403);
             return false;
         }
@@ -113,7 +116,6 @@ class LeavegroupAction extends Action
      *
      * @return void
      */
-
     function handle($args)
     {
         parent::handle($args);
@@ -126,6 +128,8 @@ class LeavegroupAction extends Action
                 Event::handle('EndLeaveGroup', array($this->group, $cur));
             }
         } catch (Exception $e) {
+            // TRANS: Server error displayed when leaving a group failed in the database.
+            // TRANS: %1$s is the leaving user's nickname, $2$s is the group nickname for which the leave failed.
             $this->serverError(sprintf(_('Could not remove user %1$s from group %2$s.'),
                                        $cur->nickname, $this->group->nickname));
             return;
@@ -134,7 +138,8 @@ class LeavegroupAction extends Action
         if ($this->boolean('ajax')) {
             $this->startHTML('text/xml;charset=utf-8');
             $this->elementStart('head');
-            $this->element('title', null, sprintf(_('%1$s left group %2$s'),
+            // TRANS: Title for leave group page after leaving.
+            $this->element('title', null, sprintf(_m('TITLE','%1$s left group %2$s'),
                                                   $cur->nickname,
                                                   $this->group->nickname));
             $this->elementEnd('head');
diff --git a/actions/recoverpassword.php b/actions/recoverpassword.php
index 33b0440e40..c41edaeea4 100644
--- a/actions/recoverpassword.php
+++ b/actions/recoverpassword.php
@@ -33,6 +33,7 @@ class RecoverpasswordAction extends Action
     {
         parent::handle($args);
         if (common_logged_in()) {
+            // TRANS: Client error displayed trying to recover password while already logged in.
             $this->clientError(_('You are already logged in!'));
             return;
         } else if ($_SERVER['REQUEST_METHOD'] == 'POST') {
@@ -41,6 +42,7 @@ class RecoverpasswordAction extends Action
             } else if ($this->arg('reset')) {
                 $this->resetPassword();
             } else {
+                // TRANS: Client error displayed when unexpected data is posted in the password recovery form.
                 $this->clientError(_('Unexpected form submission.'));
             }
         } else {
@@ -54,15 +56,16 @@ class RecoverpasswordAction extends Action
 
     function checkCode()
     {
-
         $code = $this->trimmed('code');
         $confirm = Confirm_address::staticGet('code', $code);
 
         if (!$confirm) {
+            // TRANS: Client error displayed when password recovery code is not correct.
             $this->clientError(_('No such recovery code.'));
             return;
         }
         if ($confirm->address_type != 'recover') {
+            // TRANS: Client error displayed when no proper password recovery code was submitted.
             $this->clientError(_('Not a recovery code.'));
             return;
         }
@@ -70,6 +73,7 @@ class RecoverpasswordAction extends Action
         $user = User::staticGet($confirm->user_id);
 
         if (!$user) {
+            // TRANS: Server error displayed trying to recover password without providing a user.
             $this->serverError(_('Recovery code for unknown user.'));
             return;
         }
@@ -83,6 +87,7 @@ class RecoverpasswordAction extends Action
 
         if (!$result) {
             common_log_db_error($confirm, 'DELETE', __FILE__);
+            // TRANS: Server error displayed removing a password recovery code from the database.
             $this->serverError(_('Error with confirmation code.'));
             return;
         }
@@ -94,6 +99,7 @@ class RecoverpasswordAction extends Action
             common_log(LOG_WARNING,
                        'Attempted redemption on recovery code ' .
                        'that is ' . $touched . ' seconds old. ');
+            // TRANS: Client error displayed trying to recover password with too old a recovery code.
             $this->clientError(_('This confirmation code is too old. ' .
                                    'Please start again.'));
             return;
@@ -108,6 +114,7 @@ class RecoverpasswordAction extends Action
             $result = $user->updateKeys($orig);
             if (!$result) {
                 common_log_db_error($user, 'UPDATE', __FILE__);
+                // TRANS: Server error displayed when updating a user's e-mail address in the database fails while recovering a password.
                 $this->serverError(_('Could not update user with confirmed email address.'));
                 return;
             }
@@ -149,14 +156,16 @@ class RecoverpasswordAction extends Action
             $this->elementStart('div', 'instructions');
             if ($this->mode == 'recover') {
                 $this->element('p', null,
+                               // TRANS: Page notice for password recovery page.
                                _('If you have forgotten or lost your' .
                                  ' password, you can get a new one sent to' .
                                  ' the email address you have stored' .
                                  ' in your account.'));
             } else if ($this->mode == 'reset') {
+                // TRANS: Page notice for password change page.
                 $this->element('p', null,
                                _('You have been identified. Enter a' .
-                                 ' new password below. '));
+                                 ' new password below.'));
             }
             $this->elementEnd('div');
         }
@@ -185,19 +194,24 @@ class RecoverpasswordAction extends Action
                                            'class' => 'form_settings',
                                            'action' => common_local_url('recoverpassword')));
         $this->elementStart('fieldset');
+        // TRANS: Fieldset legend for password recovery page.
         $this->element('legend', null, _('Password recovery'));
         $this->elementStart('ul', 'form_data');
         $this->elementStart('li');
+        // TRANS: Field label on password recovery page.
         $this->input('nicknameoremail', _('Nickname or email address'),
                      $this->trimmed('nicknameoremail'),
+                     // TRANS: Title for field label on password recovery page.
                      _('Your nickname on this server, ' .
                         'or your registered email address.'));
         $this->elementEnd('li');
         $this->elementEnd('ul');
         $this->element('input', array('name' => 'recover',
                                       'type' => 'hidden',
+                                      // TRANS: Field label on password recovery page.
                                       'value' => _('Recover')));
-        $this->submit('recover', _('Recover'));
+        // TRANS: Button text on password recovery page.
+        $this->submit('recover', _m('BUTTON','Recover'));
         $this->elementEnd('fieldset');
         $this->elementEnd('form');
     }
@@ -205,11 +219,16 @@ class RecoverpasswordAction extends Action
     function title()
     {
         switch ($this->mode) {
+         // TRANS: Title for password recovery page in password reset mode.
          case 'reset': return _('Reset password');
+         // TRANS: Title for password recovery page in password recover mode.
          case 'recover': return _('Recover password');
+         // TRANS: Title for password recovery page in email sent mode.
          case 'sent': return _('Password recovery requested');
+         // TRANS: Title for password recovery page in password saved mode.
          case 'saved': return _('Password saved.');
          default:
+            // TRANS: Title for password recovery page when an unknown action has been specified.
             return _('Unknown action');
         }
     }
@@ -228,19 +247,25 @@ class RecoverpasswordAction extends Action
                                            'class' => 'form_settings',
                                            'action' => common_local_url('recoverpassword')));
         $this->elementStart('fieldset');
+         // TRANS: Fieldset legend for password reset form.
         $this->element('legend', null, _('Password change'));
         $this->hidden('token', common_session_token());
         $this->elementStart('ul', 'form_data');
         $this->elementStart('li');
+         // TRANS: Field label for password reset form.
         $this->password('newpassword', _('New password'),
-                        _('6 or more characters, and don\'t forget it!'));
+                        // TRANS: Title for field label for password reset form.
+                        _('6 or more characters, and do not forget it!'));
         $this->elementEnd('li');
         $this->elementStart('li');
+         // TRANS: Field label for password reset form where the password has to be typed again.
         $this->password('confirm', _('Confirm'),
-                        _('Same as password above'));
+                        // TRANS: Ttile for field label for password reset form where the password has to be typed again.
+                        _('Same as password above.'));
         $this->elementEnd('li');
         $this->elementEnd('ul');
-        $this->submit('reset', _('Reset'));
+         // TRANS: Button text for password reset form.
+        $this->submit('reset', _m('BUTTON','Reset'));
         $this->elementEnd('fieldset');
         $this->elementEnd('form');
     }
@@ -249,6 +274,7 @@ class RecoverpasswordAction extends Action
     {
         $nore = $this->trimmed('nicknameoremail');
         if (!$nore) {
+            // TRANS: Form instructions for password recovery form.
             $this->showForm(_('Enter a nickname or email address.'));
             return;
         }
@@ -279,6 +305,7 @@ class RecoverpasswordAction extends Action
         }
 
         if (!$user) {
+            // TRANS: Information on password recovery form if no known username or e-mail address was specified.
             $this->showForm(_('No user with that email address or username.'));
             return;
         }
@@ -296,6 +323,7 @@ class RecoverpasswordAction extends Action
         }
 
         if (!$user->email && !$confirm_email) {
+            // TRANS: Client error displayed on password recovery form if a user does not have a registered e-mail address.
             $this->clientError(_('No registered email address for that user.'));
             return;
         }
@@ -310,10 +338,12 @@ class RecoverpasswordAction extends Action
 
         if (!$confirm->insert()) {
             common_log_db_error($confirm, 'INSERT', __FILE__);
+            // TRANS: Server error displayed if e-mail address confirmation fails in the database on the password recovery form.
             $this->serverError(_('Error saving address confirmation.'));
             return;
         }
 
+         // @todo FIXME: needs i18n.
         $body = "Hey, $user->nickname.";
         $body .= "\n\n";
         $body .= 'Someone just asked for a new password ' .
@@ -332,9 +362,11 @@ class RecoverpasswordAction extends Action
         $body .= "\n";
 
         $headers = _mail_prepare_headers('recoverpassword', $user->nickname, $user->nickname);
+        // TRANS: Subject for password recovery e-mail.
         mail_to_user($user, _('Password recovery requested'), $body, $headers, $confirm->address);
 
         $this->mode = 'sent';
+        // TRANS: User notification after an e-mail with instructions was sent from the password recovery form.
         $this->msg = _('Instructions for recovering your password ' .
                           'have been sent to the email address registered to your ' .
                           'account.');
@@ -347,6 +379,7 @@ class RecoverpasswordAction extends Action
         # CSRF protection
         $token = $this->trimmed('token');
         if (!$token || $token != common_session_token()) {
+            // TRANS: Form validation error message.
             $this->showForm(_('There was a problem with your session token. Try again, please.'));
             return;
         }
@@ -354,6 +387,7 @@ class RecoverpasswordAction extends Action
         $user = $this->getTempUser();
 
         if (!$user) {
+            // TRANS: Client error displayed when trying to reset as password without providing a user.
             $this->clientError(_('Unexpected password reset.'));
             return;
         }
@@ -362,10 +396,12 @@ class RecoverpasswordAction extends Action
         $confirm = $this->trimmed('confirm');
 
         if (!$newpassword || strlen($newpassword) < 6) {
+            // TRANS: Reset password form validation error message.
             $this->showPasswordForm(_('Password must be 6 characters or more.'));
             return;
         }
         if ($newpassword != $confirm) {
+            // TRANS: Reset password form validation error message.
             $this->showPasswordForm(_('Password and confirmation do not match.'));
             return;
         }
@@ -378,13 +414,15 @@ class RecoverpasswordAction extends Action
 
         if (!$user->update($original)) {
             common_log_db_error($user, 'UPDATE', __FILE__);
-            $this->serverError(_('Can\'t save new password.'));
+            // TRANS: Reset password form validation error message.
+            $this->serverError(_('Cannot save new password.'));
             return;
         }
 
         $this->clearTempUser();
 
         if (!common_set_user($user->nickname)) {
+            // TRANS: Server error displayed when something does wrong with the user object during password reset.
             $this->serverError(_('Error setting user.'));
             return;
         }
@@ -392,6 +430,7 @@ class RecoverpasswordAction extends Action
         common_real_login(true);
 
         $this->mode = 'saved';
+        // TRANS: Success message for user after password reset.
         $this->msg = _('New password successfully saved. ' .
                        'You are now logged in.');
         $this->success = true;
diff --git a/actions/register.php b/actions/register.php
index 5d91aef70e..488d8901fc 100644
--- a/actions/register.php
+++ b/actions/register.php
@@ -430,16 +430,15 @@ class RegisterAction extends Action
         if (Event::handle('StartRegistrationFormData', array($this))) {
             $this->elementStart('li');
             $this->input('nickname', _('Nickname'), $this->trimmed('nickname'),
-                         _('1-64 lowercase letters or numbers, '.
-                           'no punctuation or spaces. Required.'));
+                         _('1-64 lowercase letters or numbers, no punctuation or spaces.'));
             $this->elementEnd('li');
             $this->elementStart('li');
             $this->password('password', _('Password'),
-                            _('6 or more characters. Required.'));
+                            _('6 or more characters.'));
             $this->elementEnd('li');
             $this->elementStart('li');
             $this->password('confirm', _('Confirm'),
-                            _('Same as password above. Required.'));
+                            _('Same as password above.'));
             $this->elementEnd('li');
             $this->elementStart('li');
             if ($this->invite && $this->invite->address_type == 'email') {
diff --git a/lib/groupeditform.php b/lib/groupeditform.php
index cc25f06886..8a111b4642 100644
--- a/lib/groupeditform.php
+++ b/lib/groupeditform.php
@@ -46,13 +46,11 @@ require_once INSTALLDIR.'/lib/form.php';
  *
  * @see      UnsubscribeForm
  */
-
 class GroupEditForm extends Form
 {
     /**
      * group for user to join
      */
-
     var $group = null;
 
     /**
@@ -61,7 +59,6 @@ class GroupEditForm extends Form
      * @param Action     $out   output channel
      * @param User_group $group group to join
      */
-
     function __construct($out=null, $group=null)
     {
         parent::__construct($out);
@@ -74,7 +71,6 @@ class GroupEditForm extends Form
      *
      * @return string ID of the form
      */
-
     function id()
     {
         if ($this->group) {
@@ -89,7 +85,6 @@ class GroupEditForm extends Form
      *
      * @return string of the form class
      */
-
     function formClass()
     {
         return 'form_settings';
@@ -100,7 +95,6 @@ class GroupEditForm extends Form
      *
      * @return string URL of the action
      */
-
     function action()
     {
         if ($this->group) {
@@ -116,7 +110,6 @@ class GroupEditForm extends Form
      *
      * @return void
      */
-
     function formLegend()
     {
         $this->out->element('legend', null, _('Create a new group'));
@@ -127,7 +120,6 @@ class GroupEditForm extends Form
      *
      * @return void
      */
-
     function formData()
     {
         if ($this->group) {
@@ -151,7 +143,7 @@ class GroupEditForm extends Form
         $this->out->hidden('groupid', $id);
         $this->out->input('nickname', _('Nickname'),
                           ($this->out->arg('nickname')) ? $this->out->arg('nickname') : $nickname,
-                          _('1-64 lowercase letters or numbers, no punctuation or spaces'));
+                          _('1-64 lowercase letters or numbers, no punctuation or spaces.'));
         $this->out->elementEnd('li');
         $this->out->elementStart('li');
         $this->out->input('fullname', _('Full name'),
@@ -167,8 +159,8 @@ class GroupEditForm extends Form
         if ($desclimit == 0) {
             $descinstr = _('Describe the group or topic');
         } else {
-            $descinstr = sprintf(_m('Describe the group or topic in %d character or less',
-                                    'Describe the group or topic in %d characters or less',
+            $descinstr = sprintf(_m('Describe the group or topic in %d character or less.',
+                                    'Describe the group or topic in %d characters or less.',
                                     $desclimit),
                                  $desclimit);
         }
@@ -201,7 +193,6 @@ class GroupEditForm extends Form
      *
      * @return void
      */
-
     function formActions()
     {
         $this->out->submit('submit', _m('BUTTON','Save'));
diff --git a/lib/webcolor.php b/lib/webcolor.php
index 7f264c6741..bf791bf794 100644
--- a/lib/webcolor.php
+++ b/lib/webcolor.php
@@ -45,7 +45,6 @@ class WebColor {
      *
      * @return nothing
      */
-
     function __construct($color = null)
     {
         if (isset($color)) {
@@ -77,7 +76,9 @@ class WebColor {
             if (preg_match('/(#([0-9A-Fa-f]{3,6})\b)/u', $color) > 0) {
                 $this->setHexColor($color);
             } else {
-                $errmsg = _('%s is not a valid color!');
+                // TRANS: Web color exception thrown when a hexadecimal color code does not validate.
+                // TRANS: %s is the provided (invalid) color code.
+                $errmsg = _('%s is not a valid color! Use 3 or 6 hex characters.');
                 throw new WebColorException(sprintf($errmsg, $color));
             }
         }
@@ -115,8 +116,8 @@ class WebColor {
                                      $hexcolor[1].$hexcolor[1],
                                      $hexcolor[2].$hexcolor[2]);
         } else {
-            // TRANS: Validation error for a web colour.
-            // TRANS: %s is the provided (invalid) text for colour.
+            // TRANS: Web color exception thrown when a hexadecimal color code does not validate.
+            // TRANS: %s is the provided (invalid) color code.
             $errmsg = _('%s is not a valid color! Use 3 or 6 hex characters.');
             throw new WebColorException(sprintf($errmsg, $hexcolor));
         }