diff --git a/gtk/prefs_dlg.c b/gtk/prefs_dlg.c
index f1811a5f92..2a15eb6d74 100644
--- a/gtk/prefs_dlg.c
+++ b/gtk/prefs_dlg.c
@@ -1,7 +1,7 @@
 /* prefs_dlg.c
  * Routines for handling preferences
  *
- * $Id: prefs_dlg.c,v 1.56 2002/11/28 01:58:27 guy Exp $
+ * $Id: prefs_dlg.c,v 1.57 2002/12/20 01:48:57 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -78,7 +78,7 @@ static void	prefs_tree_select_cb(GtkTreeSelection *, gpointer);
 #define E_NAMERES_PAGE_KEY "nameres_options_page"
 #define E_TOOLTIPS_KEY     "tooltips"
 
-#define FIRST_PROTO_PREFS_PAGE	6
+static int first_proto_prefs_page = -1;
 
 /*
  * Keep a static pointer to the notebook to be able to choose the
@@ -102,14 +102,17 @@ static GtkWidget *prefs_w;
 static e_prefs saved_prefs;
 
 struct ct_struct {
+  GtkWidget    *main_vb;
   GtkWidget    *notebook;
   GtkWidget    *tree;
-#if GTK_MAJOR_VERSION >= 2
-  GtkTreeIter  proto_iter;
-#endif
+#if GTK_MAJOR_VERSION < 2
   GtkCTreeNode *node;
+#else
+  GtkTreeIter  iter;
+#endif
   GtkTooltips  *tooltips;
   gint         page;
+  gboolean     is_protocol;
 };
 
 static void
@@ -203,57 +206,108 @@ static void
 module_prefs_show(module_t *module, gpointer user_data)
 {
   struct ct_struct *cts = user_data;
+  struct ct_struct child_cts;
   GtkWidget        *main_vb, *main_tb, *frame;
   gchar            label_str[MAX_TREE_NODE_NAME_LEN];
 #if GTK_MAJOR_VERSION < 2
-  gchar           *label_ptr = label_str;
+  gchar            *label_ptr = label_str;
   GtkCTreeNode     *ct_node;
 #else
   GtkTreeStore     *model;
   GtkTreeIter      iter;
 #endif
 
-  /* Frame */
-  frame = gtk_frame_new(module->title);
-  gtk_widget_show(frame);
-
-  /* Main vertical box */
-  main_vb = gtk_vbox_new(FALSE, 5);
-  gtk_container_border_width(GTK_CONTAINER(main_vb), 5);
-  gtk_container_add(GTK_CONTAINER(frame), main_vb);
-
-  /* Main table */
-  main_tb = gtk_table_new(module->numprefs, 2, FALSE);
-  gtk_box_pack_start(GTK_BOX(main_vb), main_tb, FALSE, FALSE, 0);
-  gtk_table_set_row_spacings(GTK_TABLE(main_tb), 10);
-  gtk_table_set_col_spacings(GTK_TABLE(main_tb), 15);
-  OBJECT_SET_DATA(main_tb, E_TOOLTIPS_KEY, cts->tooltips);
-
-  /* Add items for each of the preferences */
-  prefs_pref_foreach(module, pref_show, main_tb);
-
-  gtk_notebook_append_page(GTK_NOTEBOOK(cts->notebook), frame, NULL);
+  /*
+   * Add this module to the tree.
+   */
   strcpy(label_str, module->title);
 #if GTK_MAJOR_VERSION < 2
   ct_node = gtk_ctree_insert_node(GTK_CTREE(cts->tree), cts->node, NULL,
-  		&label_ptr, 5, NULL, NULL, NULL, NULL, TRUE, TRUE);
-  gtk_ctree_node_set_row_data(GTK_CTREE(cts->tree), ct_node,
-  		GINT_TO_POINTER(cts->page));
+  		&label_ptr, 5, NULL, NULL, NULL, NULL, !module->is_subtree,
+  		FALSE);
 #else
   model = GTK_TREE_STORE(gtk_tree_view_get_model(GTK_TREE_VIEW(cts->tree)));
-  gtk_tree_store_append(model, &iter, &cts->proto_iter);
-  gtk_tree_store_set(model, &iter, 0, label_str, 1, cts->page, -1);
+  gtk_tree_store_append(model, &iter, &cts->iter);
 #endif
-  cts->page++;
 
-  /* Show 'em what we got */
-  gtk_widget_show_all(main_vb);
+  /*
+   * Is this a subtree?
+   */
+  if (module->is_subtree) {
+    /*
+     * Yes.
+     */
+
+    /* Note that there's no page attached to this item */
+#if GTK_MAJOR_VERSION < 2
+    gtk_ctree_node_set_row_data(GTK_CTREE(cts->tree), ct_node,
+  		GINT_TO_POINTER(-1));
+#else
+    gtk_tree_store_set(model, &iter, 0, label_str, 1, -1, -1);
+#endif
+
+    /*
+     * Walk the subtree and attach stuff to it.
+     */
+    child_cts = *cts;
+#if GTK_MAJOR_VERSION < 2
+    child_cts.node = ct_node;
+#else
+    child_cts.iter = iter;
+#endif
+    if (module == protocols_module)
+      child_cts.is_protocol = TRUE;
+    prefs_module_list_foreach(module->prefs, module_prefs_show, &child_cts);
+  } else {
+    /*
+     * No.
+     * Create a notebook page for it.
+     */
+
+    /* Frame */
+    frame = gtk_frame_new(module->title);
+    gtk_widget_show(frame);
+
+    /* Main vertical box */
+    main_vb = gtk_vbox_new(FALSE, 5);
+    gtk_container_border_width(GTK_CONTAINER(main_vb), 5);
+    gtk_container_add(GTK_CONTAINER(frame), main_vb);
+
+    /* Main table */
+    main_tb = gtk_table_new(module->numprefs, 2, FALSE);
+    gtk_box_pack_start(GTK_BOX(main_vb), main_tb, FALSE, FALSE, 0);
+    gtk_table_set_row_spacings(GTK_TABLE(main_tb), 10);
+    gtk_table_set_col_spacings(GTK_TABLE(main_tb), 15);
+    OBJECT_SET_DATA(main_tb, E_TOOLTIPS_KEY, cts->tooltips);
+
+    /* Add items for each of the preferences */
+    prefs_pref_foreach(module, pref_show, main_tb);
+
+    /* Add the page to the notebook */
+    gtk_notebook_append_page(GTK_NOTEBOOK(cts->notebook), frame, NULL);
+
+    /* Attach the page to the tree item */
+#if GTK_MAJOR_VERSION < 2
+    gtk_ctree_node_set_row_data(GTK_CTREE(cts->tree), ct_node,
+  		GINT_TO_POINTER(cts->page));
+#else
+    gtk_tree_store_set(model, &iter, 0, label_str, 1, cts->page, -1);
+#endif
+
+    /* If this is the first protocol page, remember its page number */
+    if (first_proto_prefs_page == -1)
+      first_proto_prefs_page = cts->page;
+    cts->page++;
+
+    /* Show 'em what we got */
+    gtk_widget_show_all(main_vb);
+  }
 }
 
 void
 prefs_cb(GtkWidget *w _U_, gpointer dummy _U_)
 {
-  GtkWidget         *main_vb, *top_hb, *bbox, *prefs_nb, *ct_sb, *frame,
+  GtkWidget         *top_hb, *bbox, *prefs_nb, *ct_sb, *frame,
                     *ok_bt, *apply_bt, *save_bt, *cancel_bt;
   GtkWidget         *print_pg, *column_pg, *stream_pg, *gui_pg;
 #ifdef HAVE_LIBPCAP
@@ -266,7 +320,6 @@ prefs_cb(GtkWidget *w _U_, gpointer dummy _U_)
   gchar             *label_ptr = label_str;
   GtkCTreeNode      *ct_node;
 #else
-  GtkTreeStore      *store;
   GtkTreeSelection  *selection;
   GtkCellRenderer   *renderer;
   GtkTreeViewColumn *column;
@@ -297,14 +350,14 @@ prefs_cb(GtkWidget *w _U_, gpointer dummy _U_)
   cts.tooltips = gtk_tooltips_new();
 
   /* Container for each row of widgets */
-  main_vb = gtk_vbox_new(FALSE, 5);
-  gtk_container_border_width(GTK_CONTAINER(main_vb), 5);
-  gtk_container_add(GTK_CONTAINER(prefs_w), main_vb);
-  gtk_widget_show(main_vb);
+  cts.main_vb = gtk_vbox_new(FALSE, 5);
+  gtk_container_border_width(GTK_CONTAINER(cts.main_vb), 5);
+  gtk_container_add(GTK_CONTAINER(prefs_w), cts.main_vb);
+  gtk_widget_show(cts.main_vb);
 
   /* Top row: Preferences tree and notebook */
   top_hb = gtk_hbox_new(FALSE, 10);
-  gtk_container_add(GTK_CONTAINER(main_vb), top_hb);
+  gtk_container_add(GTK_CONTAINER(cts.main_vb), top_hb);
   gtk_widget_show(top_hb);
 
   /* Place a Ctree on the left for preference categories */
@@ -331,7 +384,8 @@ prefs_cb(GtkWidget *w _U_, gpointer dummy _U_)
   gtk_tree_view_column_set_sizing(GTK_TREE_VIEW_COLUMN(column),
                                   GTK_TREE_VIEW_COLUMN_AUTOSIZE);
 #endif
-  cts.page  = 0;
+  cts.page = 0;
+  cts.node = NULL;
   gtk_container_add(GTK_CONTAINER(ct_sb), cts.tree);
 
 #if GTK_MAJOR_VERSION < 2
@@ -344,8 +398,8 @@ prefs_cb(GtkWidget *w _U_, gpointer dummy _U_)
 
   /* A notebook widget sans tabs is used to flip between prefs */
   notebook = prefs_nb = gtk_notebook_new();
-  gtk_notebook_set_show_tabs(GTK_NOTEBOOK(notebook), FALSE);
-  gtk_notebook_set_show_border(GTK_NOTEBOOK(notebook), FALSE);
+  gtk_notebook_set_show_tabs(GTK_NOTEBOOK(prefs_nb), FALSE);
+  gtk_notebook_set_show_border(GTK_NOTEBOOK(prefs_nb), FALSE);
   gtk_container_add(GTK_CONTAINER(top_hb), prefs_nb);
   gtk_widget_show(prefs_nb);
 
@@ -474,26 +528,14 @@ prefs_cb(GtkWidget *w _U_, gpointer dummy _U_)
 
   /* Registered prefs */
   cts.notebook = prefs_nb;
-  strcpy(label_str, "Protocols");
-#if GTK_MAJOR_VERSION < 2
-  cts.node = gtk_ctree_insert_node(GTK_CTREE(cts.tree), NULL, NULL,
-  		&label_ptr, 5, NULL, NULL, NULL, NULL, FALSE, FALSE);
-  gtk_ctree_node_set_row_data(GTK_CTREE(cts.tree), cts.node,
-  		GINT_TO_POINTER(-1));
-  gtk_ctree_node_set_selectable(GTK_CTREE(cts.tree), cts.node, FALSE);
-#else
-  gtk_tree_store_append(store, &cts.proto_iter, NULL);
-  gtk_tree_store_set(store, &cts.proto_iter, 0, label_str, 1, -1, -1);
-#endif
-
-  prefs_module_foreach(module_prefs_show, &cts);
-
+  cts.is_protocol = FALSE;
+  prefs_module_list_foreach(NULL, module_prefs_show, &cts);
 
   /* Button row: OK and cancel buttons */
   bbox = gtk_hbutton_box_new();
   gtk_button_box_set_layout (GTK_BUTTON_BOX (bbox), GTK_BUTTONBOX_END);
   gtk_button_box_set_spacing(GTK_BUTTON_BOX(bbox), 5);
-  gtk_container_add(GTK_CONTAINER(main_vb), bbox);
+  gtk_container_add(GTK_CONTAINER(cts.main_vb), bbox);
   gtk_widget_show(bbox);
 
 #if GTK_MAJOR_VERSION < 2
@@ -914,7 +956,7 @@ prefs_main_ok_cb(GtkWidget *ok_bt _U_, gpointer parent_w)
 #endif /* _WIN32 */
 #endif /* HAVE_LIBPCAP */
   nameres_prefs_fetch(OBJECT_GET_DATA(parent_w, E_NAMERES_PAGE_KEY));
-  prefs_module_foreach(module_prefs_fetch, &must_redissect);
+  prefs_modules_foreach(module_prefs_fetch, &must_redissect);
 
   /* Now apply those preferences. */
   printer_prefs_apply(OBJECT_GET_DATA(parent_w, E_PRINT_PAGE_KEY));
@@ -966,7 +1008,7 @@ prefs_main_apply_cb(GtkWidget *apply_bt _U_, gpointer parent_w)
 #endif /* _WIN32 */
 #endif /* HAVE_LIBPCAP */
   nameres_prefs_fetch(OBJECT_GET_DATA(parent_w, E_NAMERES_PAGE_KEY));
-  prefs_module_foreach(module_prefs_fetch, &must_redissect);
+  prefs_modules_foreach(module_prefs_fetch, &must_redissect);
 
   /* Now apply those preferences. */
   printer_prefs_apply(OBJECT_GET_DATA(parent_w, E_PRINT_PAGE_KEY));
@@ -1018,7 +1060,7 @@ prefs_main_save_cb(GtkWidget *save_bt _U_, gpointer parent_w)
 #endif /* _WIN32 */
 #endif /* HAVE_LIBPCAP */
   nameres_prefs_fetch(OBJECT_GET_DATA(parent_w, E_NAMERES_PAGE_KEY));
-  prefs_module_foreach(module_prefs_fetch, &must_redissect);
+  prefs_modules_foreach(module_prefs_fetch, &must_redissect);
 
   /* Create the directory that holds personal configuration files, if
      necessary.  */
@@ -1151,7 +1193,7 @@ prefs_main_cancel_cb(GtkWidget *cancel_bt _U_, gpointer parent_w)
   copy_prefs(&prefs, &saved_prefs);
 
   /* Now revert the registered preferences. */
-  prefs_module_foreach(module_prefs_revert, &must_redissect);
+  prefs_modules_foreach(module_prefs_revert, &must_redissect);
 
   /* Now apply the reverted-to preferences. */
   printer_prefs_apply(OBJECT_GET_DATA(parent_w, E_PRINT_PAGE_KEY));
@@ -1203,10 +1245,11 @@ prefs_main_destroy_cb(GtkWidget *win _U_, gpointer user_data _U_)
   /* Free up the saved preferences (both for "prefs" and for registered
      preferences). */
   free_prefs(&saved_prefs);
-  prefs_module_foreach(module_prefs_clean, NULL);
+  prefs_modules_foreach(module_prefs_clean, NULL);
 
   /* Note that we no longer have a "Preferences" dialog box. */
   prefs_w = NULL;
+  first_proto_prefs_page = -1;
 }
 
 struct properties_data {
@@ -1258,11 +1301,11 @@ properties_cb(GtkWidget *w, gpointer dummy)
   }
 
   p.w = notebook;
-  p.page_num = FIRST_PROTO_PREFS_PAGE;
+  p.page_num = first_proto_prefs_page;
   p.title = title;
 
-  prefs_module_foreach(module_search_properties, &p);
-
+  prefs_module_list_foreach(protocols_module->prefs, module_search_properties,
+      &p);
 }
 
 /* Prefs tree selection callback.  The node data has been loaded with
diff --git a/prefs-int.h b/prefs-int.h
index 15bc5d6b90..8c989bfcf1 100644
--- a/prefs-int.h
+++ b/prefs-int.h
@@ -2,7 +2,7 @@
  * Definitions for implementation of preference handling routines;
  * used by "friends" of the preferences type.
  *
- * $Id: prefs-int.h,v 1.9 2002/08/28 21:00:40 jmayer Exp $
+ * $Id: prefs-int.h,v 1.10 2002/12/20 01:48:54 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -29,14 +29,20 @@
 struct pref_module {
 	const char *name;	/* name of module */
 	const char *title;	/* title of module (displayed in preferences notebook) */
+	gboolean is_subtree;	/* if TRUE, this has other modules, not preferences, under it */
 	void (*apply_cb)(void);	/* routine to call when preferences applied */
-	GList	*prefs;		/* list of its preferences */
+	GList	*prefs;		/* list of its preferences or submodules */
 	int	numprefs;	/* number of non-obsolete preferences */
 	gboolean prefs_changed;	/* if TRUE, a preference has changed since we last checked */
 	gboolean obsolete;	/* if TRUE, this is a module that used to
 				   exist but no longer does */
 };
 
+/*
+ * Module used for protocol preferences.
+ */
+extern module_t *protocols_module;
+
 /*
  * PREF_OBSOLETE is used for preferences that a module used to support
  * but no longer supports; we give different error messages for them.
diff --git a/prefs.c b/prefs.c
index 0d31bfd077..1c4cf5487b 100644
--- a/prefs.c
+++ b/prefs.c
@@ -1,7 +1,7 @@
 /* prefs.c
  * Routines for handling preferences
  *
- * $Id: prefs.c,v 1.91 2002/09/28 15:23:13 gerald Exp $
+ * $Id: prefs.c,v 1.92 2002/12/20 01:48:54 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -51,6 +51,9 @@
 
 /* Internal functions */
 static module_t *find_module(const char *name);
+static module_t *prefs_register_module_or_subtree(module_t *parent,
+    const char *name, const char *title, gboolean is_subtree,
+    void (*apply_cb)(void));
 static struct preference *find_preference(module_t *, const char *);
 static int    set_pref(gchar*, gchar*);
 static GList *get_string_list(gchar *);
@@ -85,10 +88,16 @@ gchar	*gui_hex_dump_highlight_style_text[] =
 	{ "BOLD", "INVERSE", NULL };
 
 /*
- * List of modules with preference settings.
+ * List of all modules with preference settings.
  */
 static GList *modules;
 
+/*
+ * List of all modules that should show up at the top level of the
+ * tree in the preference dialog box.
+ */
+static GList *top_level_modules;
+
 static gint
 module_compare_name(gconstpointer p1_arg, gconstpointer p2_arg)
 {
@@ -98,15 +107,46 @@ module_compare_name(gconstpointer p1_arg, gconstpointer p2_arg)
 	return g_strcasecmp(p1->name, p2->name);
 }
 
+static gint
+module_compare_title(gconstpointer p1_arg, gconstpointer p2_arg)
+{
+	const module_t *p1 = p1_arg;
+	const module_t *p2 = p2_arg;
+
+	return g_strcasecmp(p1->title, p2->title);
+}
+
 /*
  * Register a module that will have preferences.
- * Specify the name used for the module in the preferences file, the
- * title used in the tab for it in a preferences dialog box, and a
+ * Specify the module under which to register it or NULL to register it
+ * at the top level, the name used for the module in the preferences file,
+ * the title used in the tab for it in a preferences dialog box, and a
  * routine to call back when we apply the preferences.
  */
 module_t *
-prefs_register_module(const char *name, const char *title,
+prefs_register_module(module_t *parent, const char *name, const char *title,
     void (*apply_cb)(void))
+{
+	return prefs_register_module_or_subtree(parent, name, title, FALSE,
+	    apply_cb);
+}
+
+/*
+ * Register a subtree that will have modules under it.
+ * Specify the module under which to register it or NULL to register it
+ * at the top level and the title used in the tab for it in a preferences
+ * dialog box.
+ */
+module_t *
+prefs_register_subtree(module_t *parent, const char *title)
+{
+	return prefs_register_module_or_subtree(parent, NULL, title, TRUE,
+	    NULL);
+}
+
+static module_t *
+prefs_register_module_or_subtree(module_t *parent, const char *name,
+    const char *title, gboolean is_subtree, void (*apply_cb)(void))
 {
 	module_t *module;
 	const guchar *p;
@@ -114,6 +154,7 @@ prefs_register_module(const char *name, const char *title,
 	module = g_malloc(sizeof (module_t));
 	module->name = name;
 	module->title = title;
+	module->is_subtree = is_subtree;
 	module->apply_cb = apply_cb;
 	module->prefs = NULL;	/* no preferences, to start */
 	module->numprefs = 0;
@@ -121,28 +162,69 @@ prefs_register_module(const char *name, const char *title,
 	module->obsolete = FALSE;
 
 	/*
-	 * Make sure that only lower-case ASCII letters, numbers,
-	 * underscores, and dots appear in the module name.
-	 *
-	 * Crash if there is, as that's an error in the code;
-	 * you can make the title a nice string with capitalization,
-	 * white space, punctuation, etc., but the name can be used
-	 * on the command line, and shouldn't require quoting,
-	 * shifting, etc.
+	 * Do we have a module name?
 	 */
-	for (p = name; *p != '\0'; p++)
-		g_assert(isascii(*p) &&
-		    (islower(*p) || isdigit(*p) || *p == '_' || *p == '.'));
+	if (name != NULL) {
+		/*
+		 * Yes.
+		 * Make sure that only lower-case ASCII letters, numbers,
+		 * underscores, and dots appear in the name.
+		 *
+		 * Crash if there is, as that's an error in the code;
+		 * you can make the title a nice string with capitalization,
+		 * white space, punctuation, etc., but the name can be used
+		 * on the command line, and shouldn't require quoting,
+		 * shifting, etc.
+		 */
+		for (p = name; *p != '\0'; p++)
+			g_assert(isascii(*p) &&
+			    (islower(*p) || isdigit(*p) || *p == '_' ||
+			     *p == '.'));
+
+		/*
+		 * Make sure there's not already a module with that
+		 * name.  Crash if there is, as that's an error in the
+		 * code, and the code has to be fixed not to register
+		 * more than one module with the same name.
+		 *
+		 * We search the list of all modules; the subtree stuff
+		 * doesn't require preferences in subtrees to have names
+		 * that reflect the subtree they're in (that would require
+		 * protocol preferences to have a bogus "protocol.", or
+		 * something such as that, to be added to all their names).
+		 */
+		g_assert(find_module(name) == NULL);
+
+		/*
+		 * Insert this module in the list of all modules.
+		 */
+		modules = g_list_insert_sorted(modules, module,
+		    module_compare_name);
+	} else {
+		/*
+		 * This has no name, just a title; check to make sure it's a
+		 * subtree, and crash if it's not.
+		 */
+		g_assert(is_subtree);
+	}
 
 	/*
-	 * Make sure there's not already a module with that
-	 * name.  Crash if there is, as that's an error in the
-	 * code, and the code has to be fixed not to register
-	 * more than one module with the same name.
+	 * Insert this module into the appropriate place in the display
+	 * tree.
 	 */
-	g_assert(find_module(name) == NULL);
-
-	modules = g_list_insert_sorted(modules, module, module_compare_name);
+	if (parent == NULL) {
+		/*
+		 * It goes at the top.
+		 */
+		top_level_modules = g_list_insert_sorted(top_level_modules,
+		    module, module_compare_title);
+	} else {
+		/*
+		 * It goes into the list for this module.
+		 */
+		parent->prefs = g_list_insert_sorted(parent->prefs, module,
+		    module_compare_title);
+	}
 
 	return module;
 }
@@ -150,12 +232,23 @@ prefs_register_module(const char *name, const char *title,
 /*
  * Register that a protocol has preferences.
  */
+module_t *protocols_module;
+
 module_t *
 prefs_register_protocol(int id, void (*apply_cb)(void))
 {
-	return prefs_register_module(proto_get_protocol_filter_name(id),
-				     proto_get_protocol_short_name(id),
-				     apply_cb);
+	/*
+	 * Have we yet created the "Protocols" subtree?
+	 */
+	if (protocols_module == NULL) {
+		/*
+		 * No.  Do so.
+		 */
+		protocols_module = prefs_register_subtree(NULL, "Protocols");
+	}
+	return prefs_register_module(protocols_module,
+	    proto_get_protocol_filter_name(id),
+	    proto_get_protocol_short_name(id), apply_cb);
 }
 
 /*
@@ -167,9 +260,18 @@ prefs_register_protocol_obsolete(int id)
 {
 	module_t *module;
 
-	module = prefs_register_module(proto_get_protocol_filter_name(id),
-				       proto_get_protocol_short_name(id),
-				       NULL);
+	/*
+	 * Have we yet created the "Protocols" subtree?
+	 */
+	if (protocols_module == NULL) {
+		/*
+		 * No.  Do so.
+		 */
+		protocols_module = prefs_register_subtree(NULL, "Protocols");
+	}
+	module = prefs_register_module(protocols_module,
+	    proto_get_protocol_filter_name(id),
+	    proto_get_protocol_short_name(id), NULL);
 	module->obsolete = TRUE;
 	return module;
 }
@@ -213,19 +315,41 @@ do_module_callback(gpointer data, gpointer user_data)
 }
 
 /*
- * Call a callback function, with a specified argument, for each module.
+ * Call a callback function, with a specified argument, for each module
+ * in a list of modules.  If the list is NULL, searches the top-level
+ * list in the display tree of modules.
+ *
+ * Ignores "obsolete" modules; their sole purpose is to allow old
+ * preferences for dissectors that no longer have preferences to be
+ * silently ignored in preference files.  Does not ignore subtrees,
+ * as this can be used when walking the display tree of modules.
+ */
+void
+prefs_module_list_foreach(GList *module_list, module_cb callback,
+    gpointer user_data)
+{
+	module_cb_arg_t arg;
+
+	if (module_list == NULL)
+		module_list = top_level_modules;
+
+	arg.callback = callback;
+	arg.user_data = user_data;
+	g_list_foreach(module_list, do_module_callback, &arg);
+}
+
+/*
+ * Call a callback function, with a specified argument, for each module
+ * in the list of all modules.  (This list does not include subtrees.)
+ *
  * Ignores "obsolete" modules; their sole purpose is to allow old
  * preferences for dissectors that no longer have preferences to be
  * silently ignored in preference files.
  */
 void
-prefs_module_foreach(module_cb callback, gpointer user_data)
+prefs_modules_foreach(module_cb callback, gpointer user_data)
 {
-	module_cb_arg_t arg;
-
-	arg.callback = callback;
-	arg.user_data = user_data;
-	g_list_foreach(modules, do_module_callback, &arg);
+	prefs_module_list_foreach(modules, callback, user_data);
 }
 
 static void
diff --git a/prefs.h b/prefs.h
index 297797ee6e..68097be5e5 100644
--- a/prefs.h
+++ b/prefs.h
@@ -1,7 +1,7 @@
 /* prefs.h
  * Definitions for preference handling routines
  *
- * $Id: prefs.h,v 1.41 2002/09/14 10:07:37 oabad Exp $
+ * $Id: prefs.h,v 1.42 2002/12/20 01:48:54 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -88,18 +88,27 @@ typedef struct pref_module module_t;
 
 /*
  * Register a module that will have preferences.
- * Specify the name used for the module in the preferences file, the
- * title used in the tab for it in a preferences dialog box, and a
+ * Specify the module under which to register it or NULL to register it
+ * at the top level, the name used for the module in the preferences file,
+ * the title used in the tab for it in a preferences dialog box, and a
  * routine to call back when we apply the preferences.
- * Note:
- * In case of dissectors, the specified name should be the protocol
- * name specified at the proto_register_protocol() call in order to
- * make the "Protocol Properties..." menu item work.
+ *
+ * This should not be used for dissector preferences;
+ * "prefs_register_protocol()" should be used for that, so that the
+ * preferences go under the "Protocols" subtree, and so that the
+ * name is the protocol name specified at the "proto_register_protocol()"
+ * call so that the "Protocol Properties..." menu item works.
  */
-extern module_t *prefs_register_module(const char *name, const char *title,
-    void (*apply_cb)(void));
+extern module_t *prefs_register_module(module_t *parent, const char *name,
+    const char *title, void (*apply_cb)(void));
 
-typedef void (*module_cb)(module_t *module, gpointer user_data);
+/*
+ * Register a subtree that will have modules under it.
+ * Specify the module under which to register it or NULL to register it
+ * at the top level and the title used in the tab for it in a preferences
+ * dialog box.
+ */
+extern module_t *prefs_register_subtree(module_t *parent, const char *title);
 
 /*
  * Register that a protocol has preferences.
@@ -113,12 +122,32 @@ extern module_t *prefs_register_protocol(int id, void (*apply_cb)(void));
 extern module_t *prefs_register_protocol_obsolete(int id);
 
 /*
- * Call a callback function, with a specified argument, for each module.
+ * Callback function for module list scanners.
+ */
+typedef void (*module_cb)(module_t *module, gpointer user_data);
+
+/*
+ * Call a callback function, with a specified argument, for each module
+ * in a list of modules.  If the list is NULL, searches the top-level
+ * list in the display tree of modules.
+ *
+ * Ignores "obsolete" modules; their sole purpose is to allow old
+ * preferences for dissectors that no longer have preferences to be
+ * silently ignored in preference files.  Does not ignore subtrees,
+ * as this can be used when walking the display tree of modules.
+ */
+extern void prefs_module_list_foreach(GList *module_list, module_cb callback,
+    gpointer user_data);
+
+/*
+ * Call a callback function, with a specified argument, for each module
+ * in the list of all modules.  (This list does not include subtrees.)
+ *
  * Ignores "obsolete" modules; their sole purpose is to allow old
  * preferences for dissectors that no longer have preferences to be
  * silently ignored in preference files.
  */
-extern void prefs_module_foreach(module_cb callback, gpointer user_data);
+extern void prefs_modules_foreach(module_cb callback, gpointer user_data);
 
 /*
  * Call the "apply" callback function for each module if any of its