diff --git a/README.md b/README.md
index fb0daf8..525772b 100644
--- a/README.md
+++ b/README.md
@@ -1,13 +1,26 @@
-# UECS
-**U**bpa **E**ntity-**C**omponent-**S**ystem in Unity3D-style
+```
+
+ __    __   _______   ______     _______.
+|  |  |  | |   ____| /      |   /       |
+|  |  |  | |  |__   |  ,----'  |   (----`
+|  |  |  | |   __|  |  |        \   \    
+|  `--'  | |  |____ |  `----.----)   |   
+ \______/  |_______| \______|_______/    
+                                         
+
+```
 
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+# UECS
+
+**U**bpa **E**ntity-**C**omponent-**S**ystem in Unity3D-style
+
 ## Environment
 
-- MSVC 16.5.3 +
+- VS 2019
 - C++ 17
 - CMake 16.3 +
 
diff --git a/include/UECS/CmptTag.h b/include/UECS/CmptTag.h
index 4e5166f..fd73fc5 100644
--- a/include/UECS/CmptTag.h
+++ b/include/UECS/CmptTag.h
@@ -41,6 +41,8 @@ namespace Ubpa::UECS {
 	template<typename TaggedCmpt>
 	using DecayTag_t = typename DecayTag<TaggedCmpt>::type;
 
+	// TODO: use IsInstance to simplify Is<some-tag>
+
 	template<typename TaggedCmpt>
 	struct IsLastFrame;
 	template<typename TaggedCmpt>
diff --git a/include/UECS/EntityMngr.h b/include/UECS/EntityMngr.h
index cff230d..0784736 100644
--- a/include/UECS/EntityMngr.h
+++ b/include/UECS/EntityMngr.h
@@ -27,8 +27,10 @@ namespace Ubpa::UECS {
 	public:
 		template<typename... Cmpts>
 		std::tuple<Entity, Cmpts*...> Create();
+
 		// use RTDCmptTraits
 		Entity Create(const CmptType* types, size_t num);
+
 		// call Create(const CmptType*, size_t)
 		template<typename... CmptTypes,
 			// for function overload
@@ -41,8 +43,11 @@ namespace Ubpa::UECS {
 
 		template<typename... Cmpts>
 		std::tuple<Cmpts*...> Attach(Entity);
+
 		// use RTDCmptTraits
 		void Attach(Entity, const CmptType* types, size_t num);
+
+		// call Attach(Entity, const CmptType*, size_t)
 		template<typename... CmptTypes,
 			// for function overload
 			typename = std::enable_if_t<(std::is_same_v<CmptTypes, CmptType>&&...)>>
@@ -53,8 +58,10 @@ namespace Ubpa::UECS {
 
 		template<typename... Cmpts>
 		void Detach(Entity);
+
 		// use RTDCmptTraits
 		void Detach(Entity, const CmptType* types, size_t num);
+
 		// call Detach(Entity, const CmptType*, size_t);
 		template<typename... CmptTypes,
 			// for function overload
diff --git a/include/UECS/SystemFunc.h b/include/UECS/SystemFunc.h
index 157e7d2..ae5939d 100644
--- a/include/UECS/SystemFunc.h
+++ b/include/UECS/SystemFunc.h
@@ -16,7 +16,7 @@ namespace Ubpa::UECS {
 	// 1. per entity function: [[const] Entity e, ] [size_t indexInQuery, ] <Tagged_Component>...
 	// - - tagged component: {LastFrame|Write|Latest}<Component>
 	// 2. job: empty argument list
-	// 3. runtime dynamic function: const EntityLocator* locator, void** cmpts
+	// 3. runtime dynamic function: RTDCmptsView
 	class SystemFunc {
 	public:
 		EntityQuery query;