README: Document the “--with-libiptc=shipped” option.

diff --git a/README b/README
index 96d601a..7412765 100644 (file)
--- a/README
+++ b/README
@@ -453,11 +453,16 @@ Prerequisites
     If present, the uuid plugin will check for UUID from HAL.
     <http://hal.freedesktop.org/>
 
-  * libiptc (optional, if not found a version shipped with this distribution
-    can be used if the Linux kernel headers are available)
+  * libiptc (optional)
     For querying iptables counters.
     <http://netfilter.org/>
 
+    If not found on the system, a version shipped with this distribution can
+    be used. It requires some Linux headers in /usr/include/linux. You can
+    force the build system to use the shipped version by specifying
+      --with-libiptc=shipped
+    when running the configure script.
+
   * libjvm (optional)
     Library that encapsulates the `Java Virtual Machine' (JVM). This library is
     used by the Java plugin to execute Java bytecode. See “Configuring with