This key is for content providers who want to register themselves and participate in DesignCenter desktop mode. These content providers handle only particular types of extensions, and they are not interested in participating in the custom mode setting of DesignCenter.
All information DesignCenter needs from a content provider participating in its desktop mode is stored under this key. An extension key could have any number of subkeys. The name of the subkey represents the name of the file extensions that are shown in DesignCenter. There are two types of extensions stored in the registry: content type and container type. Under the Extension Name key can be the following subkeys:
If an extension key does not have any subkeys, it is considered to be a content type extension unless a content provider specifically sets the Container key to a value of one.
If an extension key does have subkeys, it is considered to be a container type extension. Values stored at this level of the key are ignored. A container key could have any number of subkeys. Each subkey represents a type of content that the container can handle.
The following registry values demonstrate an extensions registry branch:
[HKEY_LOCAL_MACHINE\SOFTWARE\Autodesk\AutoCAD\R24.0\ ACAD-4101:409\AutodeskApps\AcadDC\Extensions] [HKEY_LOCAL_MACHINE\SOFTWARE\Autodesk\AutoCAD\R24.0\ ACAD-4101:409\AutodeskApps\AcadDC\Extensions\.dwg] "Default_CLSID"="{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}" "Default_IconIndex"=dword:00000002 "Container"=dword:00000001 [HKEY_LOCAL_MACHINE\SOFTWARE\Autodesk\AutoCAD\R24.0\ ACAD-4101:409\AutodeskApps\AcadDC\Extensions\.dwg\Blocks] "CLSID"="{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}" "IconIndex"=dword:00000000 "Prefix"="AcDc" "LocalName"="Blocks"