[4.0.x] Fixed #33338 -- Doc'd that never_cache() decorator set Expires header.

Backport of 669dcefc04837c35fc2ec5ce906d84397005965d from main

1 files changed, 4 insertions, 0 deletions

diff --git a/docs/ref/utils.txt b/docs/ref/utils.txt
index d316c8a8bf..25e5fdb2c9 100644
--- a/docs/ref/utils.txt
+++ b/docs/ref/utils.txt
@@ -62,10 +62,14 @@ need to distinguish caches by the ``Accept-language`` header.
 
 .. function:: add_never_cache_headers(response)
 
+    Adds an ``Expires`` header to the current date/time.
+
     Adds a ``Cache-Control: max-age=0, no-cache, no-store, must-revalidate,
     private`` header to a response to indicate that a page should never be
     cached.
 
+    Each header is only added if it isn't already set.
+
 .. function:: patch_vary_headers(response, newheaders)
 
     Adds (or updates) the ``Vary`` header in the given ``HttpResponse`` object.