From 8bd8d5194531f2b9b53fea93fe3413af1530138e Mon Sep 17 00:00:00 2001
From: Javier Eguiluz <javier.eguiluz@gmail.com>
Date: Fri, 8 Jan 2021 09:51:40 +0100
Subject: [PATCH] Add more details about the ESI detection

---
 http_cache/esi.rst | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/http_cache/esi.rst b/http_cache/esi.rst
index 621f604ea95..4ee07e9c939 100644
--- a/http_cache/esi.rst
+++ b/http_cache/esi.rst
@@ -156,9 +156,9 @@ used ``render()``.
 
 .. note::
 
-    Symfony detects if a gateway cache supports ESI via another Akamai
-    specification that is supported out of the box by the Symfony reverse
-    proxy.
+    Symfony considers that a gateway cache supports ESI if its responses include
+    the ``Surrogate-Capability`` HTTP header and the value of that header
+    contains the ``ESI/1.0`` string anywhere.
 
 The embedded action can now specify its own caching rules entirely independently
 of the master page::