* `cache`_

* `enable_annotations`_

* `translation_domain`_

* `strict_email`_

* `api`_

secret

**type**: ``string``

This value is used to determine the service that is used to persist class

metadata in a cache. The actual service name is built byprefix the configured

metadata in a cache. The actual service name is built byprefixing the configured

value with ``validator.mapping.cache.`` (e.g. if the value is ``apc``, the

``validator.mapping.cache.apc`` service will be injected). The service has

to implement the:class:`Symfony\\Component\\Validator\\Mapping\\Cache\\CacheInterface`.

The translation domain that is used when translating validation constraint

error messages.

strict_email

..versionadded::2.5

The ``strict_email`` option was introduced in Symfony 2.5.

**type**: ``Boolean`` **default**: ``false``

If this option is enabled, the `egulias/email-validator`_ library will be

used by the:doc:`/reference/constraints/Email` constraint validator. Otherwise,

the validator uses a simple regular expression to validate email addresses.

api

..versionadded::2.5

The ``api`` option was introduced in Symfony 2.5.

**type**: ``string``

Starting with Symfony 2.5, the Validator component introduced a new validation

API. The ``api`` option is used to switch between the different implementations:

``2.4``

Use the vaidation API that is compatible with older Symfony versions.

``2.5``

Use the validation API introduced in Symfony 2.5.

``2.5-bc`` or ``auto``

If you omit a value or set the ``api`` option to ``2.5-bc`` or ``auto``,

Symfony will use an API implementation that is compatible with both the

legacy implementation and the ``2.5`` implementation. You have to use

PHP 5.3.9 or higher to be able to use this implementation.

Full default Configuration