Mouse cursor, opening dirs/archives and tab duplication

[Vochomurka]

The mouse cursor shape depending on the user action can be:
1) Sheets with green plus (copying);
2) Sheets with red minus (moving);
3) Red crossed circle (the "not available" sign).

But there is one more symbol, and some more mouse operations. The symbol looks like the shortcut one (curved black arrow). First we have to take one or several files or directories with mouse, and then keeping the left mouse button pressed, put it in one of the following areas:
1) Top line (2 pixels high) of any tab (whether it is active or not, whether it is on the active panel or not);
2) Line (1 pixel high) above any path field;
3) Free space alongside of tabs.

All these areas are shown in series on the screenshot.

Action after the left mouse button is released depends on what objects have been dragged:
1) For files, the source tab is duplicated (each duplicate for each dragged file);
2) For directories, they are all opened in new background tabs;
3) For archives, they are also opened as directories.

So, files dragged to any of these areas cause the source tab dupliction. More, dragging directories and archives is equvalent to commands 3003 and 3004, except that the user chooses the source or target panels himself, and that tabs are opened in background.

Neither copying nor moving is performed in any case.

Questions:
1) Are these features described in totalcmd.chm and/or history.txt? If yes, where? If no, why?
2) How can they be used?

[Balderstrom]

Interesting find. Oddly though, the tabs are all appended at the END of the tab list, disregarding the setting for:
[x] Open new tabs near current tab.

It actually might be (more) useful if it was triggered by dragging to the "Tabstop" area instead of trying to find the 2px near the top of a Folder Tab.