Added paragraph about different dll versions and structure sizes.
diff --git a/documentation/common_controls b/documentation/common_controls
index ef71995..7ee3b3f 100644
--- a/documentation/common_controls
+++ b/documentation/common_controls
@@ -25,6 +25,55 @@
collected here too.
+2.1 Structure sizes of different common control versions
+--------------------------------------------------------
+ The common controls have been continously improved in the past. Some of the
+ orignal structures had to be extended and their size changed. Most of the
+ common control structures include their size as the first parameter. If
+ a control gets the wrong size in a message or function a failure is very
+ likely to occur. To avoid this, MS defined new constants that reflect the
+ structure size of older COMCTL32.DLL versions. The following list shows the
+ structure size constants that are currently defined in the original
+ COMCTL32.DLL.
+ NOTE: Some stuctures are NOT defined in wine's COMCTL32 yet.
+
+ HDITEM_V1_SIZE:
+ The size of the HDITEM structure in version 4.00.
+
+ LVCOLUMN_V1_SIZE:
+ The size of the LVCOLUMN structure in version 4.00.
+
+ LVHITTESTINFO_V1_SIZE:
+ The size of the LVHITTESTINFO structure in version 4.00.
+
+ LVITEM_V1_SIZE:
+ The size of the LVITEM structure in version 4.00.
+
+ NMLVCUSTOMDRAW_V3_SIZE:
+ The size of the NMLVCUSTOMDRAW structure in version 4.70.
+
+ NMTTDISPINFO_V1_SIZE:
+ The size of the NMTTDISPINFO structure in version 4.00.
+
+ NMTVCUSTOMDRAW_V3_SIZE:
+ The size of the NMTVCUSTOMDRAW structure in version 4.70.
+
+ PROPSHEETHEADER_V1_SIZE:
+ The size of the PROPSHEETHEADER structure in version 4.00.
+
+ PROPSHEETPAGE_V1_SIZE:
+ The size of the PROPSHEETPAGE structure in version 4.00.
+
+ REBARBANDINFO_V3_SIZE:
+ The size of the REBARBANDINFO structure in version 4.70.
+
+ TTTOOLINFO_V1_SIZE:
+ The size of the TOOLINFO structure in version 4.00.
+
+ TVINSERTSTRUCT_V1_SIZE:
+ The size of the TVINSERTSTRUCT structure in version 4.00.
+
+
3. Controls
-----------
This paragraph describes the development status of the common controls.
