diff --git a/app/Core/Lang.php b/app/Core/Lang.php
index b537bd18..8a324041 100644
--- a/app/Core/Lang.php
+++ b/app/Core/Lang.php
@@ -87,10 +87,10 @@ class Lang
                     $this->tr[$lang] = $this->arrayFromStr($file);
                 }
                 $flag = false;
-            } elseif ($lang === 'English') {
+            } elseif ($lang === 'en') {
                 $flag = false;
             }
-            $lang = 'English';
+            $lang = 'en';
         } while ($flag);
 
         $this->loaded[$name][$lang] = true;
diff --git a/app/Models/User/Model.php b/app/Models/User/Model.php
index 982e7ab7..00f5ba7f 100644
--- a/app/Models/User/Model.php
+++ b/app/Models/User/Model.php
@@ -111,14 +111,14 @@ class Model extends DataModel
     {
         $langs = $this->c->Func->getLangs();
 
-        $lang = $this->isGuest || empty($this->a['language']) || ! \in_array($this->a['language'], $langs)
+        $lang = $this->isGuest || empty($this->a['language']) || ! isset($langs[$this->a['language']])
             ? $this->c->config->o_default_lang
             : $this->a['language'];
 
-        if (\in_array($lang, $langs)) {
+        if (isset($langs[$lang])) {
             return $lang;
         } else {
-            return isset($langs[0]) ? $langs[0] : 'English';
+            return \reset($langs) ?: 'en';
         }
     }
 
@@ -131,14 +131,14 @@ class Model extends DataModel
     {
         $styles = $this->c->Func->getStyles();
 
-        $style = $this->isGuest || empty($this->a['style']) || ! \in_array($this->a['style'], $styles)
+        $style = $this->isGuest || empty($this->a['style']) || ! isset($styles[$this->a['style']])
             ? $this->c->config->o_default_style
             : $this->a['style'];
 
-        if (\in_array($style, $styles)) {
+        if (isset($styles[$style])) {
             return $style;
         } else {
-            return isset($styles[0]) ? $styles[0] : 'ForkBB';
+            return \reset($styles) ?: 'ForkBB';
         }
     }
 
diff --git a/app/config/install.php b/app/config/install.php
index a98c6fd1..a9634e89 100644
--- a/app/config/install.php
+++ b/app/config/install.php
@@ -15,7 +15,7 @@ return [
     ],
 
     'forConfig' => [
-        'o_default_lang'   => 'English',
+        'o_default_lang'   => 'en',
         'o_default_style'  => 'ForkBB',
         'o_redirect_delay' => 0,
         'o_date_format'    => 'Y-m-d',
diff --git a/app/lang/English/admin.po b/app/lang/en/admin.po
similarity index 100%
rename from app/lang/English/admin.po
rename to app/lang/en/admin.po
diff --git a/app/lang/English/admin_categories.po b/app/lang/en/admin_categories.po
similarity index 100%
rename from app/lang/English/admin_categories.po
rename to app/lang/en/admin_categories.po
diff --git a/app/lang/English/admin_censoring.po b/app/lang/en/admin_censoring.po
similarity index 100%
rename from app/lang/English/admin_censoring.po
rename to app/lang/en/admin_censoring.po
diff --git a/app/lang/English/admin_forums.po b/app/lang/en/admin_forums.po
similarity index 100%
rename from app/lang/English/admin_forums.po
rename to app/lang/en/admin_forums.po
diff --git a/app/lang/English/admin_groups.po b/app/lang/en/admin_groups.po
similarity index 100%
rename from app/lang/English/admin_groups.po
rename to app/lang/en/admin_groups.po
diff --git a/app/lang/English/admin_host.po b/app/lang/en/admin_host.po
similarity index 100%
rename from app/lang/English/admin_host.po
rename to app/lang/en/admin_host.po
diff --git a/app/lang/English/admin_index.po b/app/lang/en/admin_index.po
similarity index 100%
rename from app/lang/English/admin_index.po
rename to app/lang/en/admin_index.po
diff --git a/app/lang/English/admin_maintenance.po b/app/lang/en/admin_maintenance.po
similarity index 100%
rename from app/lang/English/admin_maintenance.po
rename to app/lang/en/admin_maintenance.po
diff --git a/app/lang/English/admin_options.po b/app/lang/en/admin_options.po
similarity index 100%
rename from app/lang/English/admin_options.po
rename to app/lang/en/admin_options.po
diff --git a/app/lang/English/admin_permissions.po b/app/lang/en/admin_permissions.po
similarity index 100%
rename from app/lang/English/admin_permissions.po
rename to app/lang/en/admin_permissions.po
diff --git a/app/lang/English/admin_users.po b/app/lang/en/admin_users.po
similarity index 100%
rename from app/lang/English/admin_users.po
rename to app/lang/en/admin_users.po
diff --git a/app/lang/English/auth.po b/app/lang/en/auth.po
similarity index 100%
rename from app/lang/English/auth.po
rename to app/lang/en/auth.po
diff --git a/app/lang/English/common.po b/app/lang/en/common.po
similarity index 100%
rename from app/lang/English/common.po
rename to app/lang/en/common.po
diff --git a/app/lang/English/delete.po b/app/lang/en/delete.po
similarity index 100%
rename from app/lang/English/delete.po
rename to app/lang/en/delete.po
diff --git a/app/lang/English/forum.po b/app/lang/en/forum.po
similarity index 100%
rename from app/lang/English/forum.po
rename to app/lang/en/forum.po
diff --git a/app/lang/English/index.po b/app/lang/en/index.po
similarity index 100%
rename from app/lang/English/index.po
rename to app/lang/en/index.po
diff --git a/app/lang/English/install.po b/app/lang/en/install.po
similarity index 100%
rename from app/lang/English/install.po
rename to app/lang/en/install.po
diff --git a/app/lang/English/mail/activate_email.tpl b/app/lang/en/mail/activate_email.tpl
similarity index 100%
rename from app/lang/English/mail/activate_email.tpl
rename to app/lang/en/mail/activate_email.tpl
diff --git a/app/lang/English/mail/banned_email_change.tpl b/app/lang/en/mail/banned_email_change.tpl
similarity index 100%
rename from app/lang/English/mail/banned_email_change.tpl
rename to app/lang/en/mail/banned_email_change.tpl
diff --git a/app/lang/English/mail/banned_email_post.tpl b/app/lang/en/mail/banned_email_post.tpl
similarity index 100%
rename from app/lang/English/mail/banned_email_post.tpl
rename to app/lang/en/mail/banned_email_post.tpl
diff --git a/app/lang/English/mail/banned_email_register.tpl b/app/lang/en/mail/banned_email_register.tpl
similarity index 100%
rename from app/lang/English/mail/banned_email_register.tpl
rename to app/lang/en/mail/banned_email_register.tpl
diff --git a/app/lang/English/mail/dupe_email_change.tpl b/app/lang/en/mail/dupe_email_change.tpl
similarity index 100%
rename from app/lang/English/mail/dupe_email_change.tpl
rename to app/lang/en/mail/dupe_email_change.tpl
diff --git a/app/lang/English/mail/dupe_email_register.tpl b/app/lang/en/mail/dupe_email_register.tpl
similarity index 100%
rename from app/lang/English/mail/dupe_email_register.tpl
rename to app/lang/en/mail/dupe_email_register.tpl
diff --git a/app/lang/English/mail/form_email.tpl b/app/lang/en/mail/form_email.tpl
similarity index 100%
rename from app/lang/English/mail/form_email.tpl
rename to app/lang/en/mail/form_email.tpl
diff --git a/app/lang/English/mail/form_pmsn.tpl b/app/lang/en/mail/form_pmsn.tpl
similarity index 100%
rename from app/lang/English/mail/form_pmsn.tpl
rename to app/lang/en/mail/form_pmsn.tpl
diff --git a/app/lang/English/mail/new_reply.tpl b/app/lang/en/mail/new_reply.tpl
similarity index 100%
rename from app/lang/English/mail/new_reply.tpl
rename to app/lang/en/mail/new_reply.tpl
diff --git a/app/lang/English/mail/new_reply_full.tpl b/app/lang/en/mail/new_reply_full.tpl
similarity index 100%
rename from app/lang/English/mail/new_reply_full.tpl
rename to app/lang/en/mail/new_reply_full.tpl
diff --git a/app/lang/English/mail/new_report.tpl b/app/lang/en/mail/new_report.tpl
similarity index 100%
rename from app/lang/English/mail/new_report.tpl
rename to app/lang/en/mail/new_report.tpl
diff --git a/app/lang/English/mail/new_topic.tpl b/app/lang/en/mail/new_topic.tpl
similarity index 100%
rename from app/lang/English/mail/new_topic.tpl
rename to app/lang/en/mail/new_topic.tpl
diff --git a/app/lang/English/mail/new_topic_full.tpl b/app/lang/en/mail/new_topic_full.tpl
similarity index 100%
rename from app/lang/English/mail/new_topic_full.tpl
rename to app/lang/en/mail/new_topic_full.tpl
diff --git a/app/lang/English/mail/new_user.tpl b/app/lang/en/mail/new_user.tpl
similarity index 100%
rename from app/lang/English/mail/new_user.tpl
rename to app/lang/en/mail/new_user.tpl
diff --git a/app/lang/English/mail/passphrase_reset.tpl b/app/lang/en/mail/passphrase_reset.tpl
similarity index 100%
rename from app/lang/English/mail/passphrase_reset.tpl
rename to app/lang/en/mail/passphrase_reset.tpl
diff --git a/app/lang/English/mail/rename.tpl b/app/lang/en/mail/rename.tpl
similarity index 100%
rename from app/lang/English/mail/rename.tpl
rename to app/lang/en/mail/rename.tpl
diff --git a/app/lang/English/mail/welcome.tpl b/app/lang/en/mail/welcome.tpl
similarity index 100%
rename from app/lang/English/mail/welcome.tpl
rename to app/lang/en/mail/welcome.tpl
diff --git a/app/lang/English/misc.po b/app/lang/en/misc.po
similarity index 100%
rename from app/lang/English/misc.po
rename to app/lang/en/misc.po
diff --git a/app/lang/English/name.php b/app/lang/en/name.php
similarity index 100%
rename from app/lang/English/name.php
rename to app/lang/en/name.php
diff --git a/app/lang/English/post.po b/app/lang/en/post.po
similarity index 100%
rename from app/lang/English/post.po
rename to app/lang/en/post.po
diff --git a/app/lang/English/profile.po b/app/lang/en/profile.po
similarity index 100%
rename from app/lang/English/profile.po
rename to app/lang/en/profile.po
diff --git a/app/lang/English/profile_other.po b/app/lang/en/profile_other.po
similarity index 100%
rename from app/lang/English/profile_other.po
rename to app/lang/en/profile_other.po
diff --git a/app/lang/English/register.po b/app/lang/en/register.po
similarity index 100%
rename from app/lang/English/register.po
rename to app/lang/en/register.po
diff --git a/app/lang/English/search.po b/app/lang/en/search.po
similarity index 100%
rename from app/lang/English/search.po
rename to app/lang/en/search.po
diff --git a/app/lang/English/stopwords.txt b/app/lang/en/stopwords.txt
similarity index 100%
rename from app/lang/English/stopwords.txt
rename to app/lang/en/stopwords.txt
diff --git a/app/lang/English/subforums.po b/app/lang/en/subforums.po
similarity index 100%
rename from app/lang/English/subforums.po
rename to app/lang/en/subforums.po
diff --git a/app/lang/English/topic.po b/app/lang/en/topic.po
similarity index 100%
rename from app/lang/English/topic.po
rename to app/lang/en/topic.po
diff --git a/app/lang/English/userlist.po b/app/lang/en/userlist.po
similarity index 100%
rename from app/lang/English/userlist.po
rename to app/lang/en/userlist.po
diff --git a/app/lang/Russian/admin.po b/app/lang/ru/admin.po
similarity index 100%
rename from app/lang/Russian/admin.po
rename to app/lang/ru/admin.po
diff --git a/app/lang/Russian/admin_categories.po b/app/lang/ru/admin_categories.po
similarity index 100%
rename from app/lang/Russian/admin_categories.po
rename to app/lang/ru/admin_categories.po
diff --git a/app/lang/Russian/admin_censoring.po b/app/lang/ru/admin_censoring.po
similarity index 100%
rename from app/lang/Russian/admin_censoring.po
rename to app/lang/ru/admin_censoring.po
diff --git a/app/lang/Russian/admin_forums.po b/app/lang/ru/admin_forums.po
similarity index 100%
rename from app/lang/Russian/admin_forums.po
rename to app/lang/ru/admin_forums.po
diff --git a/app/lang/Russian/admin_groups.po b/app/lang/ru/admin_groups.po
similarity index 100%
rename from app/lang/Russian/admin_groups.po
rename to app/lang/ru/admin_groups.po
diff --git a/app/lang/Russian/admin_host.po b/app/lang/ru/admin_host.po
similarity index 100%
rename from app/lang/Russian/admin_host.po
rename to app/lang/ru/admin_host.po
diff --git a/app/lang/Russian/admin_index.po b/app/lang/ru/admin_index.po
similarity index 100%
rename from app/lang/Russian/admin_index.po
rename to app/lang/ru/admin_index.po
diff --git a/app/lang/Russian/admin_maintenance.po b/app/lang/ru/admin_maintenance.po
similarity index 100%
rename from app/lang/Russian/admin_maintenance.po
rename to app/lang/ru/admin_maintenance.po
diff --git a/app/lang/Russian/admin_options.po b/app/lang/ru/admin_options.po
similarity index 100%
rename from app/lang/Russian/admin_options.po
rename to app/lang/ru/admin_options.po
diff --git a/app/lang/Russian/admin_permissions.po b/app/lang/ru/admin_permissions.po
similarity index 100%
rename from app/lang/Russian/admin_permissions.po
rename to app/lang/ru/admin_permissions.po
diff --git a/app/lang/Russian/admin_users.po b/app/lang/ru/admin_users.po
similarity index 100%
rename from app/lang/Russian/admin_users.po
rename to app/lang/ru/admin_users.po
diff --git a/app/lang/Russian/auth.po b/app/lang/ru/auth.po
similarity index 100%
rename from app/lang/Russian/auth.po
rename to app/lang/ru/auth.po
diff --git a/app/lang/Russian/common.po b/app/lang/ru/common.po
similarity index 100%
rename from app/lang/Russian/common.po
rename to app/lang/ru/common.po
diff --git a/app/lang/Russian/delete.po b/app/lang/ru/delete.po
similarity index 100%
rename from app/lang/Russian/delete.po
rename to app/lang/ru/delete.po
diff --git a/app/lang/Russian/forum.po b/app/lang/ru/forum.po
similarity index 100%
rename from app/lang/Russian/forum.po
rename to app/lang/ru/forum.po
diff --git a/app/lang/Russian/index.po b/app/lang/ru/index.po
similarity index 100%
rename from app/lang/Russian/index.po
rename to app/lang/ru/index.po
diff --git a/app/lang/Russian/install.po b/app/lang/ru/install.po
similarity index 100%
rename from app/lang/Russian/install.po
rename to app/lang/ru/install.po
diff --git a/app/lang/Russian/mail/activate_email.tpl b/app/lang/ru/mail/activate_email.tpl
similarity index 100%
rename from app/lang/Russian/mail/activate_email.tpl
rename to app/lang/ru/mail/activate_email.tpl
diff --git a/app/lang/Russian/mail/banned_email_change.tpl b/app/lang/ru/mail/banned_email_change.tpl
similarity index 100%
rename from app/lang/Russian/mail/banned_email_change.tpl
rename to app/lang/ru/mail/banned_email_change.tpl
diff --git a/app/lang/Russian/mail/banned_email_post.tpl b/app/lang/ru/mail/banned_email_post.tpl
similarity index 100%
rename from app/lang/Russian/mail/banned_email_post.tpl
rename to app/lang/ru/mail/banned_email_post.tpl
diff --git a/app/lang/Russian/mail/banned_email_register.tpl b/app/lang/ru/mail/banned_email_register.tpl
similarity index 100%
rename from app/lang/Russian/mail/banned_email_register.tpl
rename to app/lang/ru/mail/banned_email_register.tpl
diff --git a/app/lang/Russian/mail/dupe_email_change.tpl b/app/lang/ru/mail/dupe_email_change.tpl
similarity index 100%
rename from app/lang/Russian/mail/dupe_email_change.tpl
rename to app/lang/ru/mail/dupe_email_change.tpl
diff --git a/app/lang/Russian/mail/dupe_email_register.tpl b/app/lang/ru/mail/dupe_email_register.tpl
similarity index 100%
rename from app/lang/Russian/mail/dupe_email_register.tpl
rename to app/lang/ru/mail/dupe_email_register.tpl
diff --git a/app/lang/Russian/mail/form_email.tpl b/app/lang/ru/mail/form_email.tpl
similarity index 100%
rename from app/lang/Russian/mail/form_email.tpl
rename to app/lang/ru/mail/form_email.tpl
diff --git a/app/lang/Russian/mail/form_pmsn.tpl b/app/lang/ru/mail/form_pmsn.tpl
similarity index 100%
rename from app/lang/Russian/mail/form_pmsn.tpl
rename to app/lang/ru/mail/form_pmsn.tpl
diff --git a/app/lang/Russian/mail/new_reply.tpl b/app/lang/ru/mail/new_reply.tpl
similarity index 100%
rename from app/lang/Russian/mail/new_reply.tpl
rename to app/lang/ru/mail/new_reply.tpl
diff --git a/app/lang/Russian/mail/new_reply_full.tpl b/app/lang/ru/mail/new_reply_full.tpl
similarity index 100%
rename from app/lang/Russian/mail/new_reply_full.tpl
rename to app/lang/ru/mail/new_reply_full.tpl
diff --git a/app/lang/Russian/mail/new_report.tpl b/app/lang/ru/mail/new_report.tpl
similarity index 100%
rename from app/lang/Russian/mail/new_report.tpl
rename to app/lang/ru/mail/new_report.tpl
diff --git a/app/lang/Russian/mail/new_topic.tpl b/app/lang/ru/mail/new_topic.tpl
similarity index 100%
rename from app/lang/Russian/mail/new_topic.tpl
rename to app/lang/ru/mail/new_topic.tpl
diff --git a/app/lang/Russian/mail/new_topic_full.tpl b/app/lang/ru/mail/new_topic_full.tpl
similarity index 100%
rename from app/lang/Russian/mail/new_topic_full.tpl
rename to app/lang/ru/mail/new_topic_full.tpl
diff --git a/app/lang/Russian/mail/new_user.tpl b/app/lang/ru/mail/new_user.tpl
similarity index 100%
rename from app/lang/Russian/mail/new_user.tpl
rename to app/lang/ru/mail/new_user.tpl
diff --git a/app/lang/Russian/mail/passphrase_reset.tpl b/app/lang/ru/mail/passphrase_reset.tpl
similarity index 100%
rename from app/lang/Russian/mail/passphrase_reset.tpl
rename to app/lang/ru/mail/passphrase_reset.tpl
diff --git a/app/lang/Russian/mail/rename.tpl b/app/lang/ru/mail/rename.tpl
similarity index 100%
rename from app/lang/Russian/mail/rename.tpl
rename to app/lang/ru/mail/rename.tpl
diff --git a/app/lang/Russian/mail/welcome.tpl b/app/lang/ru/mail/welcome.tpl
similarity index 100%
rename from app/lang/Russian/mail/welcome.tpl
rename to app/lang/ru/mail/welcome.tpl
diff --git a/app/lang/Russian/misc.po b/app/lang/ru/misc.po
similarity index 100%
rename from app/lang/Russian/misc.po
rename to app/lang/ru/misc.po
diff --git a/app/lang/Russian/name.php b/app/lang/ru/name.php
similarity index 100%
rename from app/lang/Russian/name.php
rename to app/lang/ru/name.php
diff --git a/app/lang/Russian/post.po b/app/lang/ru/post.po
similarity index 100%
rename from app/lang/Russian/post.po
rename to app/lang/ru/post.po
diff --git a/app/lang/Russian/profile.po b/app/lang/ru/profile.po
similarity index 100%
rename from app/lang/Russian/profile.po
rename to app/lang/ru/profile.po
diff --git a/app/lang/Russian/profile_other.po b/app/lang/ru/profile_other.po
similarity index 100%
rename from app/lang/Russian/profile_other.po
rename to app/lang/ru/profile_other.po
diff --git a/app/lang/Russian/register.po b/app/lang/ru/register.po
similarity index 100%
rename from app/lang/Russian/register.po
rename to app/lang/ru/register.po
diff --git a/app/lang/Russian/search.po b/app/lang/ru/search.po
similarity index 100%
rename from app/lang/Russian/search.po
rename to app/lang/ru/search.po
diff --git a/app/lang/Russian/stopwords.txt b/app/lang/ru/stopwords.txt
similarity index 100%
rename from app/lang/Russian/stopwords.txt
rename to app/lang/ru/stopwords.txt
diff --git a/app/lang/Russian/subforums.po b/app/lang/ru/subforums.po
similarity index 100%
rename from app/lang/Russian/subforums.po
rename to app/lang/ru/subforums.po
diff --git a/app/lang/Russian/topic.po b/app/lang/ru/topic.po
similarity index 100%
rename from app/lang/Russian/topic.po
rename to app/lang/ru/topic.po
diff --git a/app/lang/Russian/userlist.po b/app/lang/ru/userlist.po
similarity index 100%
rename from app/lang/Russian/userlist.po
rename to app/lang/ru/userlist.po