view doc: warn against split-horizon DNS

diff --git a/modules/view/README.rst b/modules/view/README.rst
index 71c13ab19b5b77ef63e2d638a6767ebf068e998b..b29c52d63bb7f7fd617afc8bd6bc9a2c3660c395 100644 (file)
--- a/modules/view/README.rst
+++ b/modules/view/README.rst
@@ -23,6 +23,14 @@ You can combine this information with :ref:`policy <mod-policy>` rules.
 This fill force given client subnet to TCP for names in ``example.com``.
 You can combine view selectors with RPZ_ to create personalized filters for example.
 
+.. warning::
+
+       Beware that cache is shared by *all* requests.  For example, it is safe
+       to refuse answer based on who asks the resolver, but trying to serve
+       different data to different clients may result in surprises.
+       Such setups are usually called **split-horizon** or similarly.
+
+
 Example configuration
 ^^^^^^^^^^^^^^^^^^^^^