Macintosh only: With a Macintosh one-button-mouse you have to simulate pressing the right mouse button by pressing Ctrl. Press the apple key for copying instead of moving the block.
OS/2 only: You are also allowed to drag text file icons to a specific position of
the text area. This will read the file. If you press SHIFT while dragging, the
name of the file without directories is copied instead of the file content. Pressing
CTRL-SHIFT copies the whole filename with directory names. Reverse, you are
allowed to drop marked text to a desktop folder. You will automatically get a filename,
based on the beginning text of the marked block. (I'm
sorry, but Windows does not offer such a functionality.)