Add a note about salt length

Apparently it is confusing that you don't specify a specific salt,
but a salt length.

(cherry picked from commit 9ddc23b2bfcbbb327a876a57b0f8313fd036507a)

diff --git a/doc/arm/reference.rst b/doc/arm/reference.rst
index cf2cef2957868e88e6e0c0ee3b19a0fbd37f8b7e..a7030ee32e85f7d8012d82922a0e74eb23e424a4 100644 (file)
--- a/doc/arm/reference.rst
+++ b/doc/arm/reference.rst
@@ -5047,7 +5047,9 @@ The following options can be specified in a ``dnssec-policy`` statement:
 
     The default is to use NSEC.  The ``iterations``, ``optout`` and
     ``salt-length`` parts are optional, but if not set, the values in
-    the example above are the default NSEC3 parameters.
+    the example above are the default NSEC3 parameters. Note that you don't
+    specify a specific salt string, ``named`` will create a salt for you
+    of the provided salt length.
 
   ``zone-propagation-delay``
     This is the expected propagation delay from the time when a zone is