diff --git a/Docs/README.gui b/Docs/README.gui
index 0c7ce88bf..9faa9124a 100644
--- a/Docs/README.gui
+++ b/Docs/README.gui
@@ -400,6 +400,7 @@ The flags printed after the node type have the following meaning:
   W       ->  trace write operations
   A       ->  archive bit set
   U       ->  user archive bit set
+  P       ->  preserved bit set (value is preserved on sim-reset)
   T       ->  property is "tied"
 
   Ln      ->  number of listeners attached to this node
diff --git a/Nasal/debug.nas b/Nasal/debug.nas
index 97e6a850e..14b0224ee 100644
--- a/Nasal/debug.nas
+++ b/Nasal/debug.nas
@@ -134,8 +134,9 @@ var attributes = func(p, verbose = 1) {
 	var W = p.getAttribute("trace-write") ? "W" : "";
 	var A = p.getAttribute("archive")     ? "A" : "";
 	var U = p.getAttribute("userarchive") ? "U" : "";
+	var P = p.getAttribute("preserve")    ? "P" : "";
 	var T = p.getAttribute("tied")        ? "T" : "";
-	var attr = r ~ w ~ R ~ W ~ A ~ U ~ T;
+	var attr = r ~ w ~ R ~ W ~ A ~ U ~ P ~ T;
 	var type = "(" ~ p.getType();
 	if (size(attr))
 		type ~= ", " ~ attr;
diff --git a/preferences.xml b/preferences.xml
index 3c13c6e7a..62cf00e9b 100644
--- a/preferences.xml
+++ b/preferences.xml
@@ -39,29 +39,29 @@ Started September 2000 by David Megginson, david@megginson.com
 		<intl include="Translations/locale.xml"/>
 		<aircraft>c172p</aircraft>
 		<virtual-cockpit type="bool">false</virtual-cockpit>
-		<presets>
+		<presets preserve="y">
 			<airport-id>KSFO</airport-id>
 			<runway></runway>
 			<trim type="bool">true</trim>
 		</presets>
 		<startup>
-			<xsize type="int">800</xsize>
-			<ysize type="int">600</ysize>
+			<xsize type="int" preserve="y">800</xsize>
+			<ysize type="int" preserve="y">600</ysize>
 			<splash-screen type="bool">true</splash-screen>
 			<splash-progress type="bool">true</splash-progress>
 			<splash-title>
 				<!-- -->
 			</splash-title>
 			<intro-music type="bool">false</intro-music>
-			<game-mode type="bool">false</game-mode>
-			<fullscreen type="bool">false</fullscreen>
+			<game-mode type="bool" preserve="y">false</game-mode>
+			<fullscreen type="bool" preserve="y">false</fullscreen>
 			<units>feet</units>
 			<save-on-exit type="bool"
 										userarchive="y">true</save-on-exit>
 			<browser-app write="n">firefox -new-tab "%u"</browser-app>
 			<!--  help viewer; only used under Unix -->
 			<terminal-ansi-colors type="bool">true</terminal-ansi-colors>
-			<season type="string">summer</season>
+			<season type="string" preserve="y">summer</season>
 		</startup>
 		<rendering>
 			<debug type="bool">false</debug>
@@ -655,7 +655,7 @@ Started September 2000 by David Megginson, david@megginson.com
 			</autovisibility>
 		</menubar>
 
-		<gui>
+		<gui preserve="y">
 			<current-style type="int"
 										 userarchive="y">1</current-style>
 			<style n="0"
@@ -722,7 +722,7 @@ Started September 2000 by David Megginson, david@megginson.com
 		</ai>
 
 		<multiplay>
-			<chat type="string">Hello</chat>
+			<chat type="string" preserve="y">Hello</chat>
 			<transmission-freq-hz type="string">118500000</transmission-freq-hz>
 			<chat-display type="bool"
 										userarchive="y">true</chat-display>
@@ -732,7 +732,7 @@ Started September 2000 by David Megginson, david@megginson.com
 		</multiplay>
 
 		<user>
-			<callsign type="string">Golf Foxtrot Sierra</callsign>
+			<callsign type="string" preserve="y">Golf Foxtrot Sierra</callsign>
 		</user>
 
 		<timing-statistics>