doc: add reference to ipaddr in IP matching

doc/userguide/rules/datasets.rst

@@ -1,3 +1,5 @@
+.. _datasets:
+
 Datasets
 ========
 

doc/userguide/rules/intro.rst

@@ -166,6 +166,11 @@ $HOME_NET                           Your setting of HOME_NET in yaml
    You cannot write a signature using ``$EXTERNAL_NET`` because it evaluates to
    'not any', which is an invalid value.
 
+.. note::
+
+   Please note that the source and destination address can also be matched via the ``ip.src`` and ``ip.dst`` keywords (See :ref:`ipaddr`). These
+   keywords are mostly used in conjuction with the dataset feature (:ref:`datasets`).
+
 Ports (source and destination)
 ------------------------------
 .. container:: example-rule

doc/userguide/rules/ipaddr.rst

@@ -1,3 +1,5 @@
+.. _ipaddr:
+
 IP Addresses Match
 ==================