diff --git a/application/displayblock.class.inc.php b/application/displayblock.class.inc.php
index a161d31b2..0ba948631 100644
--- a/application/displayblock.class.inc.php
+++ b/application/displayblock.class.inc.php
@@ -470,7 +470,8 @@ class DisplayBlock
 					$bDisplayMenu = isset($aExtraParams['menu']) ? $aExtraParams['menu'] == true : true; 
 					if ($bDisplayMenu)
 					{
-						if (UserRights::IsActionAllowed($sClass, UR_ACTION_MODIFY) == UR_ALLOWED_YES)
+						if ((UserRights::IsActionAllowed($sClass, UR_ACTION_MODIFY) == UR_ALLOWED_YES)
+							&& !MetaModel::IsReadOnlyClass($sClass))
 						{
 							$oAppContext = new ApplicationContext();
 							$sParams = $oAppContext->GetForLink();
@@ -512,7 +513,8 @@ class DisplayBlock
 				$bDisplayMenu = isset($this->m_aParams['menu']) ? $this->m_aParams['menu'] == true : true; 
 				if ($bDisplayMenu)
 				{
-					if (UserRights::IsActionAllowed($sClass, UR_ACTION_MODIFY) == UR_ALLOWED_YES)
+					if ((UserRights::IsActionAllowed($sClass, UR_ACTION_MODIFY) == UR_ALLOWED_YES)
+						&& (!MetaModel::IsReadOnlyClass($sClass)))
 					{
 						$oAppContext = new ApplicationContext();
 						$sParams = $oAppContext->GetForLink();
@@ -552,7 +554,8 @@ class DisplayBlock
 			break;
 
 			case 'modify':
-			if (UserRights::IsActionAllowed($this->m_oSet->GetClass(), UR_ACTION_MODIFY, $this->m_oSet) == UR_ALLOWED_YES)
+			if ((UserRights::IsActionAllowed($this->m_oSet->GetClass(), UR_ACTION_MODIFY, $this->m_oSet) == UR_ALLOWED_YES)
+				&& !MetaModel::IsReadOnlyClass($this->m_oSet->GetClass()))
 			{
 				while($oObj = $this->m_oSet->Fetch())
 				{
@@ -884,17 +887,17 @@ class MenuBlock extends DisplayBlock
 		{
 			case 0:
 			// No object in the set, the only possible action is "new"
-			$bIsModifyAllowed = (!MetaModel::IsAbstract($sClass)) && UserRights::IsActionAllowed($sClass, UR_ACTION_MODIFY);
+			$bIsModifyAllowed = (!MetaModel::IsAbstract($sClass)) && (UserRights::IsActionAllowed($sClass, UR_ACTION_MODIFY) == UR_ALLOWED_YES) && !MetaModel::IsReadOnlyClass($sClass);
 			if ($bIsModifyAllowed) { $aActions[] = array ('label' => Dict::S('UI:Menu:New'), 'url' => "../page/$sUIPage?operation=new&class=$sClass&$sContext{$sDefault}"); }
 			break;
 			
 			case 1:
 			$oObj = $oSet->Fetch();
 			$id = $oObj->GetKey();
-			$bIsModifyAllowed = (!MetaModel::IsAbstract($sClass)) && UserRights::IsActionAllowed($sClass, UR_ACTION_MODIFY, $oSet);
-			$bIsDeleteAllowed = UserRights::IsActionAllowed($sClass, UR_ACTION_DELETE, $oSet);
-			$bIsBulkModifyAllowed = (!MetaModel::IsAbstract($sClass)) && UserRights::IsActionAllowed($sClass, UR_ACTION_BULK_MODIFY, $oSet);
-			$bIsBulkDeleteAllowed = UserRights::IsActionAllowed($sClass, UR_ACTION_BULK_DELETE, $oSet);
+			$bIsModifyAllowed = (!MetaModel::IsAbstract($sClass)) && (UserRights::IsActionAllowed($sClass, UR_ACTION_MODIFY, $oSet) == UR_ALLOWED_YES) && !MetaModel::IsReadOnlyClass($sClass);
+			$bIsDeleteAllowed = UserRights::IsActionAllowed($sClass, UR_ACTION_DELETE, $oSet) && !MetaModel::IsReadOnlyClass($sClass);
+			$bIsBulkModifyAllowed = (!MetaModel::IsAbstract($sClass)) && UserRights::IsActionAllowed($sClass, UR_ACTION_BULK_MODIFY, $oSet) && !MetaModel::IsReadOnlyClass($sClass);
+			$bIsBulkDeleteAllowed = UserRights::IsActionAllowed($sClass, UR_ACTION_BULK_DELETE, $oSet) && !MetaModel::IsReadOnlyClass($sClass);
 			// Just one object in the set, possible actions are "new / clone / modify and delete"
 			if (isset($aExtraParams['link_attr']))
 			{
@@ -942,16 +945,16 @@ class MenuBlock extends DisplayBlock
 			default:
 			// Check rights
 			// New / Modify
-			$bIsModifyAllowed = (!MetaModel::IsAbstract($sClass)) && UserRights::IsActionAllowed($sClass, UR_ACTION_MODIFY, $oSet);
-			$bIsBulkModifyAllowed = (!MetaModel::IsAbstract($sClass)) && UserRights::IsActionAllowed($sClass, UR_ACTION_BULK_MODIFY, $oSet);
-			$bIsBulkDeleteAllowed = UserRights::IsActionAllowed($sClass, UR_ACTION_BULK_DELETE, $oSet);
+			$bIsModifyAllowed = (!MetaModel::IsAbstract($sClass)) && UserRights::IsActionAllowed($sClass, UR_ACTION_MODIFY, $oSet) && !MetaModel::IsReadOnlyClass($sClass);
+			$bIsBulkModifyAllowed = (!MetaModel::IsAbstract($sClass)) && UserRights::IsActionAllowed($sClass, UR_ACTION_BULK_MODIFY, $oSet) && !MetaModel::IsReadOnlyClass($sClass);
+			$bIsBulkDeleteAllowed = UserRights::IsActionAllowed($sClass, UR_ACTION_BULK_DELETE, $oSet) && !MetaModel::IsReadOnlyClass($sClass);
 			if (isset($aExtraParams['link_attr']))
 			{
 				$id = $aExtraParams['object_id'];
 				$sTargetAttr = $aExtraParams['target_attr'];
 				$oAttDef = MetaModel::GetAttributeDef($sClass, $sTargetAttr);
 				$sTargetClass = $oAttDef->GetTargetClass();
-				$bIsDeleteAllowed = UserRights::IsActionAllowed($sClass, UR_ACTION_DELETE, $oSet);
+				$bIsDeleteAllowed = UserRights::IsActionAllowed($sClass, UR_ACTION_DELETE, $oSet) && !MetaModel::IsReadOnlyClass($sClass);
 				if ($bIsModifyAllowed) { $aActions[] = array ('label' => Dict::S('UI:Menu:Add'), 'url' => "../pages/$sUIPage?operation=modify_links&class=$sClass&link_attr=".$aExtraParams['link_attr']."&target_class=$sTargetClass&id=$id&addObjects=true&$sContext"); }
 				//if ($bIsBulkModifyAllowed) { $aActions[] = array ('label' => 'Add...', 'url' => "../pages/$sUIPage?operation=modify_links&class=$sClass&linkage=".$aExtraParams['linkage']."&id=$id&addObjects=true&$sContext"); }
 				if ($bIsBulkModifyAllowed) { $aActions[] = array ('label' => Dict::S('UI:Menu:Manage'), 'url' => "../pages/$sUIPage?operation=modify_links&class=$sClass&link_attr=".$aExtraParams['link_attr']."&target_class=$sTargetClass&id=$id&sContext"); }
diff --git a/core/cmdbchange.class.inc.php b/core/cmdbchange.class.inc.php
index a4bc1d8c5..81d617ed3 100644
--- a/core/cmdbchange.class.inc.php
+++ b/core/cmdbchange.class.inc.php
@@ -51,6 +51,10 @@ class CMDBChange extends DBObject
 		MetaModel::Init_AddAttribute(new AttributeString("userinfo", array("allowed_values"=>null, "sql"=>"userinfo", "default_value"=>null, "is_null_allowed"=>true, "depends_on"=>array())));
 	}
 
+	static public function IsReadOnly()
+	{
+		return true;
+	}
 }
 
 ?>
diff --git a/core/cmdbchangeop.class.inc.php b/core/cmdbchangeop.class.inc.php
index a8e6f8c81..ffff1493a 100644
--- a/core/cmdbchangeop.class.inc.php
+++ b/core/cmdbchangeop.class.inc.php
@@ -57,6 +57,12 @@ class CMDBChangeOp extends DBObject
 		MetaModel::Init_SetZListItems('details', array('change', 'date', 'userinfo')); // Attributes to be displayed for the complete details
 		MetaModel::Init_SetZListItems('list', array('change', 'date', 'userinfo')); // Attributes to be displayed for the complete details
 	}
+
+	static public function IsReadOnly()
+	{
+		return true;
+	}
+
 	/**
 	 * Describe (as a text string) the modifications corresponding to this change
 	 */	 
diff --git a/core/dbobject.class.php b/core/dbobject.class.php
index d892065c4..b874f9dbb 100644
--- a/core/dbobject.class.php
+++ b/core/dbobject.class.php
@@ -76,6 +76,12 @@ abstract class DBObject
 		}
 	}
 
+	// Read-only <=> Written once (archive)
+	static public function IsReadOnly()
+	{
+		return false;
+	}
+
 	public function RegisterAsDirty()
 	{
 		// While the object may be written to the DB, it is NOT possible to reload it
diff --git a/core/event.class.inc.php b/core/event.class.inc.php
index 0b4099a7b..303f4d0f4 100644
--- a/core/event.class.inc.php
+++ b/core/event.class.inc.php
@@ -55,6 +55,11 @@ class Event extends cmdbAbstractObject
 //		MetaModel::Init_SetZListItems('standard_search', array('name')); // Criteria of the std search form
 //		MetaModel::Init_SetZListItems('advanced_search', array('name')); // Criteria of the advanced search form
 	}
+
+	static public function IsReadOnly()
+	{
+		return true;
+	}
 }
 
 class EventNotification extends Event
diff --git a/core/metamodel.class.php b/core/metamodel.class.php
index dd7d829a5..bb4d6fcdd 100644
--- a/core/metamodel.class.php
+++ b/core/metamodel.class.php
@@ -226,6 +226,12 @@ abstract class MetaModel
 		return self::GetParentPersistentClass($sClass);
 	}
 
+	static public function IsReadOnlyClass($sClass)
+	{
+		$bReadOnly = call_user_func(array($sClass, 'IsReadOnly'));
+		return $bReadOnly;
+	}
+
 	final static public function GetName($sClass)
 	{
 		self::_check_subclass($sClass);
diff --git a/pages/UI.php b/pages/UI.php
index a714807f5..ab9186825 100644
--- a/pages/UI.php
+++ b/pages/UI.php
@@ -48,7 +48,7 @@ function DeleteObjects(WebPage $oP, $sClass, $aObjects, $bDeleteConfirmed)
 			foreach ($aDeletes as $iId => $aData)
 			{
 				$oToDelete = $aData['to_delete'];
-				$bDeleteAllowed = UserRights::IsActionAllowed($sClass, UR_ACTION_DELETE, DBObjectSet::FromObject($oToDelete));
+				$bDeleteAllowed = UserRights::IsActionAllowed($sClass, UR_ACTION_DELETE, DBObjectSet::FromObject($oToDelete)) && !MetaModel::IsReadOnlyClass($sClass);
 				$aTotalDeletedObjs[$sRemoteClass][$iId]['auto_delete'] = $aData['auto_delete'];
 				if (!$bDeleteAllowed)
 				{
@@ -605,7 +605,7 @@ try
 				$oObj = $oSet->Fetch();
 			}
 		
-			$bIsModifiedAllowed = (UserRights::IsActionAllowed($sClass, UR_ACTION_MODIFY, $oSet) == UR_ALLOWED_YES);
+			$bIsModifiedAllowed = (UserRights::IsActionAllowed($sClass, UR_ACTION_MODIFY, $oSet) == UR_ALLOWED_YES) && !MetaModel::IsReadOnlyClass($sClass);
 			$bIsReadAllowed = (UserRights::IsActionAllowed($sClass, UR_ACTION_READ, $oSet) == UR_ALLOWED_YES);
 			if( ($oObj != null) && ($bIsModifiedAllowed) && ($bIsReadAllowed))
 			{
@@ -642,7 +642,7 @@ try
 			$oObjToClone = $oSet->Fetch();
 		}
 	
-		$bIsModifiedAllowed = (UserRights::IsActionAllowed($sClass, UR_ACTION_MODIFY, $oSet) == UR_ALLOWED_YES);
+		$bIsModifiedAllowed = (UserRights::IsActionAllowed($sClass, UR_ACTION_MODIFY, $oSet) == UR_ALLOWED_YES) && !MetaModel::IsReadOnlyClass($sClass);
 		$bIsReadAllowed = (UserRights::IsActionAllowed($sClass, UR_ACTION_READ, $oSet) == UR_ALLOWED_YES);
 		if( ($oObjToClone != null) && ($bIsModifiedAllowed) && ($bIsReadAllowed))
 		{
@@ -894,7 +894,7 @@ try
 			{
 				$aObjects[] = $oContext->GetObject($sClass, $iId);
 			}
-			if (!UserRights::IsActionAllowed($sClass, UR_ACTION_BULK_DELETE, DBObjectSet::FromArray($sClass, $aObjects)))
+			if (MetaModel::IsReadOnlyClass($sClass) || !UserRights::IsActionAllowed($sClass, UR_ACTION_BULK_DELETE, DBObjectSet::FromArray($sClass, $aObjects)))
 			{
 				throw new SecurityException(Dict::S('UI:Error:BulkDeleteNotAllowedOn_Class'), $sClass);
 			}
@@ -909,7 +909,7 @@ try
 		$id = utils::ReadParam('id', '');
 		$oObj = $oContext->GetObject($sClass, $id);
 	
-		if (!UserRights::IsActionAllowed($sClass, UR_ACTION_MODIFY, DBObjectSet::FromObject($oObj)))
+		if (MetaModel::IsReadOnlyClass($sClass) || !UserRights::IsActionAllowed($sClass, UR_ACTION_MODIFY, DBObjectSet::FromObject($oObj)))
 		{
 			throw new SecurityException(Dict::S('UI:Error:DeleteNotAllowedOn_Class'), $sClass);
 		}