diff --git a/phpBB/phpbb/captcha/plugins/incomplete.php b/phpBB/phpbb/captcha/plugins/incomplete.php
index 9669931761..5c2b7f9a66 100644
--- a/phpBB/phpbb/captcha/plugins/incomplete.php
+++ b/phpBB/phpbb/captcha/plugins/incomplete.php
@@ -1,48 +1,108 @@
 <?php
+/**
+ *
+ * This file is part of the phpBB Forum Software package.
+ *
+ * @copyright (c) phpBB Limited <https://www.phpbb.com>
+ * @license GNU General Public License, version 2 (GPL-2.0)
+ *
+ * For full copyright and license information, please see
+ * the docs/CREDITS.txt file.
+ *
+ */
 
 namespace phpbb\captcha\plugins;
 
 use phpbb\config\config;
 use phpbb\template\template;
 
-class incomplete extends \phpbb\captcha\plugins\captcha_abstract
+class incomplete extends captcha_abstract
 {
+	/**
+	 * Constructor for incomplete captcha
+	 *
+	 * @param config $config
+	 * @param template $template
+	 * @param string $phpbb_root_path
+	 * @param string $phpEx
+	 */
 	public function __construct(protected config $config, protected template $template,
 								protected string $phpbb_root_path, protected string $phpEx)
 	{}
 
-	public function is_available()
+	/**
+	 * @return bool True if captcha is available, false if not
+	 */
+	public function is_available(): bool
 	{
 		return true;
 	}
 
+	/**
+	 * Dummy implementation
+	 *
+	 * @return void
+	 */
 	public function get_generator_class()
 	{
 	}
 
-	public static function get_name()
+	/**
+	 * Get CAPTCHA name language variable
+	 *
+	 * @return string Language variable
+	 */
+	public static function get_name(): string
 	{
 		return 'CAPTCHA_INCOMPLETE';
 	}
 
+	/**
+	 * Init CAPTCHA
+	 *
+	 * @param int $type CAPTCHA type
+	 * @return void
+	 */
 	public function init($type)
 	{
 	}
 
+	/**
+	 * Execute demo
+	 *
+	 * @return void
+	 */
 	public function execute_demo()
 	{
 	}
 
+	/**
+	 * Execute CAPTCHA
+	 *
+	 * @return void
+	 */
 	public function execute()
 	{
 	}
 
-	public function get_demo_template($id)
+	/**
+	 * Get template data for demo
+	 *
+	 * @param int|string $id ACP module ID
+	 *
+	 * @return string Demo template file name
+	 */
+	public function get_demo_template($id): string
 	{
 		return '';
 	}
 
-	public function get_template()
+	/**
+	 * Get template data for CAPTCHA
+	 *
+	 * @return string CAPTCHA template file name
+	 */
+	public function get_template(): string
 	{
 		$contact_link = phpbb_get_board_contact_link($this->config, $this->phpbb_root_path, $this->phpEx);
 
@@ -54,13 +114,23 @@ class incomplete extends \phpbb\captcha\plugins\captcha_abstract
 		return 'captcha_incomplete.html';
 	}
 
-	public function validate()
+	/**
+	 * Validate CAPTCHA
+	 *
+	 * @return false Incomplete CAPTCHA will never validate
+	 */
+	public function validate(): bool
 	{
 		return false;
 	}
 
-	public function is_solved()
+	/**
+	 * Check whether CAPTCHA is solved
+	 *
+	 * @return false Incomplete CAPTCHA will never be solved
+	 */
+	public function is_solved(): bool
 	{
 		return false;
 	}
-}
\ No newline at end of file
+}