diff --git a/src/Controllers/PostController.php b/src/Controllers/PostController.php
index ea0bda07..28e3dbaf 100644
--- a/src/Controllers/PostController.php
+++ b/src/Controllers/PostController.php
@@ -680,7 +680,7 @@ class PostController
 					->innerJoin('tag')
 					->on('post_tag.tag_id = tag.id')
 					->where('post_id = post.id')
-					->and('tag.name = ?')->put($val)
+					->and('LOWER(tag.name) = LOWER(?)')->put($val)
 					->close();
 				continue;
 			}
diff --git a/src/Models/Model_Comment.php b/src/Models/Model_Comment.php
index e8fd37d5..12c8b11c 100644
--- a/src/Models/Model_Comment.php
+++ b/src/Models/Model_Comment.php
@@ -1,11 +1,15 @@
 <?php
 class Model_Comment extends RedBean_SimpleModel
 {
-	public static function locate($key)
+	public static function locate($key, $throw = true)
 	{
 		$comment = R::findOne('comment', 'id = ?', [$key]);
 		if (!$comment)
-			throw new SimpleException('Invalid comment ID "' . $key . '"');
+		{
+			if ($throw)
+				throw new SimpleException('Invalid comment ID "' . $key . '"');
+			return null;
+		}
 		return $comment;
 	}
 
diff --git a/src/Models/Model_Post.php b/src/Models/Model_Post.php
index 7ee8ad42..ecdb564c 100644
--- a/src/Models/Model_Post.php
+++ b/src/Models/Model_Post.php
@@ -1,19 +1,27 @@
 <?php
 class Model_Post extends RedBean_SimpleModel
 {
-	public static function locate($key, $disallowNumeric = false)
+	public static function locate($key, $disallowNumeric = false, $throw = true)
 	{
 		if (is_numeric($key) and !$disallowNumeric)
 		{
 			$post = R::findOne('post', 'id = ?', [$key]);
 			if (!$post)
-				throw new SimpleException('Invalid post ID "' . $key . '"');
+			{
+				if ($throw)
+					throw new SimpleException('Invalid post ID "' . $key . '"');
+				return null;
+			}
 		}
 		else
 		{
 			$post = R::findOne('post', 'name = ?', [$key]);
 			if (!$post)
-				throw new SimpleException('Invalid post name "' . $key . '"');
+			{
+				if ($throw)
+					throw new SimpleException('Invalid post name "' . $key . '"');
+				return null;
+			}
 		}
 		return $post;
 	}
diff --git a/src/Models/Model_Tag.php b/src/Models/Model_Tag.php
index 1cf64662..03e44831 100644
--- a/src/Models/Model_Tag.php
+++ b/src/Models/Model_Tag.php
@@ -1,12 +1,16 @@
 <?php
 class Model_Tag extends RedBean_SimpleModel
 {
-	public static function locate($key)
+	public static function locate($key, $throw = true)
 	{
-		$user = R::findOne('tag', 'name = ?', [$key]);
-		if (!$user)
-			throw new SimpleException('Invalid tag name "' . $key . '"');
-		return $user;
+		$tag = R::findOne('tag', 'LOWER(name) = LOWER(?)', [$key]);
+		if (!$tag)
+		{
+			if ($throw)
+				throw new SimpleException('Invalid tag name "' . $key . '"');
+			return null;
+		}
+		return $tag;
 	}
 
 	public static function insertOrUpdate($tags)
@@ -14,7 +18,7 @@ class Model_Tag extends RedBean_SimpleModel
 		$dbTags = [];
 		foreach ($tags as $tag)
 		{
-			$dbTag = R::findOne('tag', 'name = ?', [$tag]);
+			$dbTag = self::locate($tag, false);
 			if (!$dbTag)
 			{
 				$dbTag = R::dispense('tag');
diff --git a/src/Models/Model_User.php b/src/Models/Model_User.php
index 119d6e7a..4a3f7aa4 100644
--- a/src/Models/Model_User.php
+++ b/src/Models/Model_User.php
@@ -1,11 +1,15 @@
 <?php
 class Model_User extends RedBean_SimpleModel
 {
-	public static function locate($key)
+	public static function locate($key, $throw = true)
 	{
 		$user = R::findOne('user', 'name = ?', [$key]);
 		if (!$user)
-			throw new SimpleException('Invalid user name "' . $key . '"');
+		{
+			if ($throw)
+				throw new SimpleException('Invalid user name "' . $key . '"');
+			return null;
+		}
 		return $user;
 	}