[acc] clarify need for extra radius dictionary

modules/acc/README

@@ -36,6 +36,7 @@ Irina-Maria Stanescu
               1.2.1. Overview
               1.2.2. Definitions and syntax
               1.2.3. How it works
+              1.2.4. Radius accounting dependencies
 
         1.3. Multi Call-Legs accounting
 
@@ -261,6 +262,12 @@ modparam("acc", "extra_fields", "log: a -> test_a")
    only by setting $acc_etra(a) variable. Else the field shall be
    log with no value(null).
 
+1.2.4. Radius accounting dependencies
+
+   If radius accounting is used, except from a radius client which
+   is mandatory, dictionary.rfc2866 must be used in order for the
+   module to work properly.
+
 1.3. Multi Call-Legs accounting
 
 1.3.1. Overview

modules/acc/doc/acc_admin.xml

@@ -198,6 +198,13 @@ modparam("acc", "extra_fields", "log: a -> test_a")
 				Else the field shall be log with no value(null).
 			</para>
 		</section>
+		<section>
+			<title>Radius accounting dependencies</title>
+			<para>
+				If radius accounting is used, except from a radius client library which is mandatory,
+				<emphasis role='bold'>dictionary.rfc2866</emphasis> must be included for the module
+				to work properly.</para>
+		</section>
 	</section>
 
 	<section id="multi-call-legs">