diff --git a/PlotSquared/pom.xml b/PlotSquared/pom.xml
index b2efb340b..1a1db655a 100644
--- a/PlotSquared/pom.xml
+++ b/PlotSquared/pom.xml
@@ -8,7 +8,7 @@
 	    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 	</properties>
     <artifactId>PlotSquared</artifactId>
-    <version>2.11.23</version>
+    <version>2.11.24</version>
     <name>PlotSquared</name>
     <packaging>jar</packaging>
     <build>
diff --git a/PlotSquared/src/main/java/com/intellectualcrafters/plot/PlotSquared.java b/PlotSquared/src/main/java/com/intellectualcrafters/plot/PlotSquared.java
index f86e96ee7..777545427 100644
--- a/PlotSquared/src/main/java/com/intellectualcrafters/plot/PlotSquared.java
+++ b/PlotSquared/src/main/java/com/intellectualcrafters/plot/PlotSquared.java
@@ -718,6 +718,7 @@ public class PlotSquared {
         for (final String flag : intFlags) {
             FlagManager.addFlag(new AbstractFlag(flag, new FlagValue.UnsignedIntegerValue()));
         }
+        FlagManager.addFlag(new AbstractFlag("modified-blocks", new FlagValue.IntegerValue()), true);
         FlagManager.addFlag(new AbstractFlag("disable-physics", new FlagValue.BooleanValue()));
         FlagManager.addFlag(new AbstractFlag("fly", new FlagValue.BooleanValue()));
         FlagManager.addFlag(new AbstractFlag("explosion", new FlagValue.BooleanValue()));
diff --git a/PlotSquared/src/main/java/com/intellectualcrafters/plot/commands/FlagCmd.java b/PlotSquared/src/main/java/com/intellectualcrafters/plot/commands/FlagCmd.java
index 4414a483a..8503b914e 100644
--- a/PlotSquared/src/main/java/com/intellectualcrafters/plot/commands/FlagCmd.java
+++ b/PlotSquared/src/main/java/com/intellectualcrafters/plot/commands/FlagCmd.java
@@ -71,6 +71,10 @@ public class FlagCmd extends SubCommand {
             MainUtil.sendMessage(player, C.NO_PERMISSION, "plots.set.flag.other");
             return false;
         }
+        if (args.length > 1 && FlagManager.isReserved(args[1])) {
+            MainUtil.sendMessage(player, C.NOT_VALID_FLAG);
+            return false;
+        }
         switch (args[0].toLowerCase()) {
             case "info": {
                 if (!Permissions.hasPermission(player, "plots.set.flag")) {
diff --git a/PlotSquared/src/main/java/com/intellectualcrafters/plot/commands/Set.java b/PlotSquared/src/main/java/com/intellectualcrafters/plot/commands/Set.java
index fe718a0dd..1fa044b8b 100644
--- a/PlotSquared/src/main/java/com/intellectualcrafters/plot/commands/Set.java
+++ b/PlotSquared/src/main/java/com/intellectualcrafters/plot/commands/Set.java
@@ -106,7 +106,7 @@ public class Set extends SubCommand {
             } catch (final Exception e) {
                 af = new AbstractFlag(args[1].toLowerCase());
             }
-            if (!FlagManager.getFlags().contains(af)) {
+            if (!FlagManager.getFlags().contains(af) || FlagManager.isReserved(af.getKey())) {
                 MainUtil.sendMessage(plr, C.NOT_VALID_FLAG);
                 return false;
             }
diff --git a/PlotSquared/src/main/java/com/intellectualcrafters/plot/flag/FlagManager.java b/PlotSquared/src/main/java/com/intellectualcrafters/plot/flag/FlagManager.java
index 837c8ad61..3e8b9181a 100644
--- a/PlotSquared/src/main/java/com/intellectualcrafters/plot/flag/FlagManager.java
+++ b/PlotSquared/src/main/java/com/intellectualcrafters/plot/flag/FlagManager.java
@@ -50,8 +50,44 @@ public class FlagManager {
     // - Plot clear interval
     // - Mob cap
     // - customized plot composition
+    
+    private final static HashSet<String> reserved = new HashSet<>();
+    
     private final static HashSet<AbstractFlag> flags = new HashSet<>();
 
+    /**
+     * Reserve a flag so that it cannot be set by players
+     * @param flag
+     */
+    public static void reserveFlag(String flag) {
+        reserved.add(flag);
+    }
+    
+    /**
+     * Get if a flag is reserved
+     * @param flag
+     * @return
+     */
+    public static boolean isReserved(String flag) {
+        return reserved.contains(flag);
+    }
+    
+    /**
+     * Get the reserved flags
+     * @return
+     */
+    public static HashSet<String> getReservedFlags() {
+        return (HashSet<String>) reserved.clone();
+    }
+    
+    /**
+     * Unreserve a flag
+     * @param flag
+     */
+    public static void unreserveFlag(String flag) {
+        reserved.remove(flag);
+    }
+    
     /**
      * Register an AbstractFlag with PlotSquared
      *
@@ -60,6 +96,10 @@ public class FlagManager {
      * @return boolean success
      */
     public static boolean addFlag(AbstractFlag af) {
+        return addFlag(af, false);
+    }
+    
+    public static boolean addFlag(AbstractFlag af, boolean reserved) {
         PlotSquared.log(C.PREFIX.s() + "&8 - Adding flag: &7" + af);
         for (PlotWorld plotworld : PlotSquared.getPlotWorldObjects()) {
             Flag flag = plotworld.DEFAULT_FLAGS.get(af.getKey());
@@ -75,7 +115,11 @@ public class FlagManager {
                 }
             }
         }
-        return (getFlag(af.getKey()) == null) && flags.add(af);
+        if ((getFlag(af.getKey()) == null) && flags.add(af)) {
+            if (reserved) reserveFlag(af.getKey());
+            return true;
+        }
+        return false;
     }
 
     public static Flag getSettingFlag(final String world, final PlotSettings settings, final String id) {