diff --git a/code/nel/tools/3d/object_viewer_qt/src/extension_system/iplugin.h b/code/nel/tools/3d/object_viewer_qt/src/extension_system/iplugin.h
index 300b8cfb1..8e7bb60f7 100644
--- a/code/nel/tools/3d/object_viewer_qt/src/extension_system/iplugin.h
+++ b/code/nel/tools/3d/object_viewer_qt/src/extension_system/iplugin.h
@@ -33,6 +33,14 @@ namespace NLMISC
 namespace NLQT
 {
 
+/**
+@interface IPlugin
+@brief Base class for all plugins.
+@details The IPlugin class is an abstract class that must be implemented 
+once for each plugin. The IPlugin implementation must be exported and 
+made known to Qt's plugin system via the Q_EXPORT_PLUGIN macro, 
+see the Qt documentation for details on that.
+*/
 class IPlugin
 {
 public:
diff --git a/code/nel/tools/3d/object_viewer_qt/src/extension_system/iplugin_manager.h b/code/nel/tools/3d/object_viewer_qt/src/extension_system/iplugin_manager.h
index dbcdb8463..e9485dbea 100644
--- a/code/nel/tools/3d/object_viewer_qt/src/extension_system/iplugin_manager.h
+++ b/code/nel/tools/3d/object_viewer_qt/src/extension_system/iplugin_manager.h
@@ -28,6 +28,14 @@ namespace NLQT
 {
 class IPluginSpec;
 
+
+/**
+@interface IPluginManager
+@brief Interface for plugin system that manages the plugins, their life cycle and their registered objects.
+@details The plugin manager is used for the following tasks:
+- Manage plugins and their state
+- Manipulate a 'common object pool'
+*/
 class IPluginManager: public QObject
 {
 	Q_OBJECT
diff --git a/code/nel/tools/3d/object_viewer_qt/src/extension_system/iplugin_spec.h b/code/nel/tools/3d/object_viewer_qt/src/extension_system/iplugin_spec.h
index c0d7ee67c..617c240c3 100644
--- a/code/nel/tools/3d/object_viewer_qt/src/extension_system/iplugin_spec.h
+++ b/code/nel/tools/3d/object_viewer_qt/src/extension_system/iplugin_spec.h
@@ -26,7 +26,12 @@ namespace NLQT
 {
 class IPlugin;
 class IPluginManager;
-
+
+/**
+@struct State
+@details The plugin goes through several steps while being loaded.
+The state gives a hint on what went wrong in case of an error.
+*/
 struct State
 {
 	enum List
@@ -41,6 +46,14 @@ struct State
 	};
 };
 
+/**
+@interface IPluginSpec
+@brief Interface for plugin spec contains the information of the plugins and 
+information about the plugin's current state.
+@details The plugin spec is also filled with more information as the plugin
+goes through its loading process (see State).
+If an error occurs, the plugin spec is the place to look for the error details.
+*/
 class IPluginSpec
 {
 public: