Apr 7, 2019 · Apr 7, 2019
diff --git a/http_cache.rst b/http_cache.rst

 When you're in debug mode (the second argument of ``Kernel`` constructor in the
 front controller is ``true``), Symfony automatically adds an ``X-Symfony-Cache``
 header to the response. Use this to get information about cache hits and misses.
 header to the response. You can also use the ``trace_level`` config
 option and set it to either ``none``, ``short`` or ``full`` to
 add this information.

 ``short`` will add the information for the master request only.
 It's written in a concise way that makes it easy to record the
 information in your server log files. For example, in Apache you can
 use ``%{X-Symfony-Cache}o`` in ``LogFormat`` format statements.
 This information can be used to extract general information about
 cache efficiency of your routes.

 .. tip::

    You can change the name of the header used for the trace
    information using the ``trace_header`` config option.

 .. versionadded:: 4.3

    The ``trace_level`` and ``trace_header`` configuration options
    were introduced in Symfony 4.3.

 .. _http-cache-symfony-versus-varnish:
Original file line number	Diff line number	Diff line change
Expand Up		@@ -155,7 +155,26 @@ For a full list of the options and their meaning, see the

		When you're in debug mode (the second argument of ``Kernel`` constructor in the
		front controller is ``true``), Symfony automatically adds an ``X-Symfony-Cache``
		header to the response. Use this to get information about cache hits and misses.
		header to the response. You can also use the ``trace_level`` config
		option and set it to either ``none``, ``short`` or ``full`` to
		add this information.

		``short`` will add the information for the master request only.
		It's written in a concise way that makes it easy to record the
		information in your server log files. For example, in Apache you can
		use ``%{X-Symfony-Cache}o`` in ``LogFormat`` format statements.
		This information can be used to extract general information about
		cache efficiency of your routes.

		.. tip::

		You can change the name of the header used for the trace
		information using the ``trace_header`` config option.

		.. versionadded:: 4.3

		The ``trace_level`` and ``trace_header`` configuration options
		were introduced in Symfony 4.3.

		.. _http-cache-symfony-versus-varnish:

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