@@ -73,6 +73,7 @@ Configuration
7373 *:ref: `enabled <reference-csrf_protection-enabled >`
7474
7575* `default_locale `_
76+ * `disallow_search_engine_index `_
7677* `esi `_
7778
7879 *:ref: `enabled <reference-esi-enabled >`
@@ -384,6 +385,21 @@ method.
384385 You can read more information about the default locale in
385386:ref: `translation-default-locale `.
386387
388+ disallow_search_engine_index
389+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
390+
391+ **type **: ``boolean `` **default **: ``true `` when the debug mode is enabled, ``false `` otherwise.
392+
393+ ..versionadded ::4.3
394+
395+ The ``disallow_search_engine_index `` option was introduced in Symfony 4.3.
396+
397+ If ``true ``, Symfony adds a ``X-Robots-Tag: noindex `` HTTP tag to all responses
398+ (unless your own app adds that header, in which case it's not modified). This
399+ `X-Robots-Tag HTTP header `_ tells search engines to not index your web site.
400+ This option is a protection measure in case you accidentally publish your site
401+ in debug mode.
402+
387403trusted_hosts
388404~~~~~~~~~~~~~
389405
@@ -2340,3 +2356,4 @@ a :doc:`normal workflow </workflow/usage>` or a :doc:`state machine </workflow/s
23402356.. _`CSRF security attacks` :https://en.wikipedia.org/wiki/Cross-site_request_forgery
23412357.. _`session.sid_length PHP option` :https://php.net/manual/session.configuration.php#ini.session.sid-length
23422358.. _`session.sid_bits_per_character PHP option` :https://php.net/manual/session.configuration.php#ini.session.sid-bits-per-character
2359+ .. _`X-Robots-Tag HTTP header` :https://developers.google.com/search/reference/robots_meta_tag