Deprecation: #67471 - Deprecate init.php 

Description 

In order to move all unneeded files from typo3/, the often used init.php has been deprecated in favor of using the bootstrap initialization code directly in the TYPO3 Backend.

Impact 

All entry points from third-party extensions using init.php will now throw a deprecation warning.

Affected Installations 

All instances having extensions that include init.php when not using the mod.php for modules or ajax calls.

Migration 

Use the following code instead of the init.php inclusion if you still need custom entry points:

define('TYPO3_MODE', 'BE');

require __DIR__ . '/sysext/core/Classes/Core/Bootstrap.php';
\TYPO3\CMS\Core\Core\Bootstrap::getInstance()->run('typo3/');

If using a module, use the mod.php to register your own module.