diff --git a/imgui.cpp b/imgui.cpp
index f1abeaae..a03e6003 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -4087,7 +4087,7 @@ void ImGui::EndFrame()
     }
 
     // Hide implicit "Debug" window if it hasn't been used
-    IM_ASSERT(g.CurrentWindowStack.Size == 1);    // Mismatched Begin()/End() calls
+    IM_ASSERT(g.CurrentWindowStack.Size == 1);    // Mismatched Begin()/End() calls, did you forget to call end on g.CurrentWindow->Name?
     if (g.CurrentWindow && !g.CurrentWindow->WriteAccessed)
         g.CurrentWindow->Active = false;
     End();
@@ -11220,7 +11220,7 @@ bool ImGui::Selectable(const char* label, bool selected, ImGuiSelectableFlags fl
         return false;
     }
 
-    // We use NoHoldingActiveID on menus so that use can click and hold on menu and drag to browse child entries
+    // We use NoHoldingActiveID on menus so user can click and _hold_ on a menu then drag to browse child entries
     ImGuiButtonFlags button_flags = 0;
     if (flags & ImGuiSelectableFlags_NoHoldingActiveID) button_flags |= ImGuiButtonFlags_NoHoldingActiveID;
     if (flags & ImGuiSelectableFlags_PressedOnClick) button_flags |= ImGuiButtonFlags_PressedOnClick;
diff --git a/imgui_internal.h b/imgui_internal.h
index d6772953..6a424dd0 100644
--- a/imgui_internal.h
+++ b/imgui_internal.h
@@ -33,16 +33,25 @@
 // Forward Declarations
 //-----------------------------------------------------------------------------
 
-struct ImRect;
-struct ImGuiColMod;
-struct ImGuiStyleMod;
-struct ImGuiGroupData;
-struct ImGuiMenuColumns;
-struct ImGuiDrawContext;
-struct ImGuiTextEditState;
-struct ImGuiPopupRef;
-struct ImGuiWindow;
-struct ImGuiWindowSettings;
+struct ImRect;                      // An axis-aligned rectangle (2 points)
+struct ImDrawDataBuilder;           // Helper to build a ImDrawData instance
+struct ImDrawListSharedData;        // Data shared between all ImDrawList instances
+struct ImGuiColMod;                 // Stacked color modifier, backup of modified data so we can restore it
+struct ImGuiColumnData;             // Storage data for a single column
+struct ImGuiColumnsSet;             // Storage data for a columns set
+struct ImGuiContext;                // Main imgui context
+struct ImGuiGroupData;              // Stacked storage data for BeginGroup()/EndGroup()
+struct ImGuiItemHoveredDataBackup;  // Backup and restore IsItemHovered() internal data
+struct ImGuiMenuColumns;            // Simple column measurement, currently used for MenuItem() only
+struct ImGuiNavMoveResult;          // Result of a directional navigation move query result
+struct ImGuiNextWindowData;         // Storage for SetNexWindow** functions
+struct ImGuiPopupRef;               // Storage for current popup stack
+struct ImGuiSettingsHandler;
+struct ImGuiStyleMod;               // Stacked style modifier, backup of modified data so we can restore it
+struct ImGuiTextEditState;          // Internal state of the currently focused/edited text input box
+struct ImGuiWindow;                 // Storage for one window
+struct ImGuiWindowTempData;         // Temporary storage for one, that's the data which in theory we could ditch at the end of the frame
+struct ImGuiWindowSettings;         // Storage for window settings stored in .ini file (we keep one of those even if the actual window wasn't instanced during this session)
 
 typedef int ImGuiLayoutType;        // enum: horizontal or vertical             // enum ImGuiLayoutType_
 typedef int ImGuiButtonFlags;       // flags: for ButtonEx(), ButtonBehavior()  // enum ImGuiButtonFlags_
@@ -372,7 +381,7 @@ struct ImGuiStyleMod
     ImGuiStyleMod(ImGuiStyleVar idx, ImVec2 v)  { VarIdx = idx; BackupFloat[0] = v.x; BackupFloat[1] = v.y; }
 };
 
-// Stacked data for BeginGroup()/EndGroup()
+// Stacked storage data for BeginGroup()/EndGroup()
 struct ImGuiGroupData
 {
     ImVec2      BackupCursorPos;
@@ -386,7 +395,7 @@ struct ImGuiGroupData
     bool        AdvanceCursor;
 };
 
-// Simple column measurement currently used for MenuItem() only. This is very short-sighted/throw-away code and NOT a generic helper.
+// Simple column measurement, currently used for MenuItem() only.. This is very short-sighted/throw-away code and NOT a generic helper.
 struct IMGUI_API ImGuiMenuColumns
 {
     int         Count;
@@ -424,7 +433,7 @@ struct IMGUI_API ImGuiTextEditState
     void                OnKeyPressed(int key);
 };
 
-// Data saved in imgui.ini file
+// Windows data saved in imgui.ini file
 struct ImGuiWindowSettings
 {
     char*       Name;
@@ -501,6 +510,7 @@ struct ImGuiColumnsSet
     }
 };
 
+// Data shared between all ImDrawList instances
 struct IMGUI_API ImDrawListSharedData
 {
     ImVec2          TexUvWhitePixel;            // UV of white pixel in the atlas
@@ -579,7 +589,7 @@ struct ImGuiNextWindowData
     }
 };
 
-// Main state for ImGui
+// Main imgui context
 struct ImGuiContext
 {
     bool                    Initialized;
@@ -832,9 +842,9 @@ enum ImGuiItemFlags_
     ImGuiItemFlags_Default_                     = ImGuiItemFlags_AllowKeyboardFocus
 };
 
-// Transient per-window data, reset at the beginning of the frame
-// FIXME: That's theory, in practice the delimitation between ImGuiWindow and ImGuiDrawContext is quite tenuous and could be reconsidered.
-struct IMGUI_API ImGuiDrawContext
+// Transient per-window data, reset at the beginning of the frame. This used to be called ImGuiDrawContext, hence the DC variable name in ImGuiWindow.
+// FIXME: That's theory, in practice the delimitation between ImGuiWindow and ImGuiWindowTempData is quite tenuous and could be reconsidered.
+struct IMGUI_API ImGuiWindowTempData
 {
     ImVec2                  CursorPos;
     ImVec2                  CursorPosPrevLine;
@@ -879,7 +889,7 @@ struct IMGUI_API ImGuiDrawContext
     float                   ColumnsOffsetX;         // Offset to the current column (if ColumnsCurrent > 0). FIXME: This and the above should be a stack to allow use cases like Tree->Column->Tree. Need revamp columns API.
     ImGuiColumnsSet*        ColumnsSet;             // Current columns set
 
-    ImGuiDrawContext()
+    ImGuiWindowTempData()
     {
         CursorPos = CursorPosPrevLine = CursorStartPos = CursorMaxPos = ImVec2(0.0f, 0.0f);
         CurrentLineHeight = PrevLineHeight = 0.0f;
@@ -911,7 +921,7 @@ struct IMGUI_API ImGuiDrawContext
     }
 };
 
-// Windows data
+// Storage for one window
 struct IMGUI_API ImGuiWindow
 {
     char*                   Name;
@@ -956,7 +966,7 @@ struct IMGUI_API ImGuiWindow
     ImVec2                  SetWindowPosVal;                    // store window position when using a non-zero Pivot (position set needs to be processed when we know the window size)
     ImVec2                  SetWindowPosPivot;                  // store window pivot for positioning. ImVec2(0,0) when positioning from top-left corner; ImVec2(0.5f,0.5f) for centering; ImVec2(1,1) for bottom right.
 
-    ImGuiDrawContext        DC;                                 // Temporary per-window data, reset at the beginning of the frame
+    ImGuiWindowTempData     DC;                                 // Temporary per-window data, reset at the beginning of the frame. This used to be called ImGuiDrawContext, hence the "DC" variable name.
     ImVector<ImGuiID>       IDStack;                            // ID stack. ID are hashes seeded with the value at the top of the stack
     ImRect                  ClipRect;                           // Current clipping rectangle. = DrawList->clip_rect_stack.back(). Scissoring / clipping rectangle. x1, y1, x2, y2.
     ImRect                  OuterRectClipped;                   // = WindowRect just after setup in Begin(). == window->Rect() for root window.