Since Stata will remember its windowing preferences between sessions,
we decided that the way to avoid confusion among some users was to
not dock the Review and Variables windows and instead let users
position them exactly where they wanted them. In the future, we may
add a preference so that users can choose to dock these windows.
For what it's worth, all of the major applications with floating
windows that I'm aware of do not dock their floating windows.
Microsoft Word and Adobe Photoshop come to mind. Although they look
like regular document windows, they're more similar to tool
palettes--they just happen to use text rather than icons.