diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index ee14284..3813e84c 100644
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -48,15 +48,25 @@ typedef unsigned int nf_hookfn(unsigned int hooknum,
 			       const struct net_device *out,
 			       int (*okfn)(struct sk_buff *));
 
+/**
+ * @list:	List anchor for parent (nf_hooks[pf][hooknum])
+ *
+ * To be filled in by user:
+ * @hook:	Function to call
+ * @owner:	Owning module
+ * @priv:	Private data, free for use by op owner
+ * @pf:		Netfilter protocol/subsystem this hook is for (%NFPROTO_*)
+ * @hooknum:	Hook this op is on (%NF_INET_*)
+ * @priority:	Hooks are ordered in ascending priority.
+ */
 struct nf_hook_ops {
 	struct list_head list;
 
-	/* User fills in from here down. */
 	nf_hookfn *hook;
 	struct module *owner;
+	void *priv;
 	u_int8_t pf;
 	unsigned int hooknum;
-	/* Hooks are ordered in ascending priority. */
 	int priority;
 };