bafe0478_ROX_Filer_User_Manual__Key_or_mouse_button
[Action] Show a menu of possible actions. There is an option to disable this menu, in which case this gesture will copy the file(s) to the destination (an application or another filer window). Hold down Shift to move the file, Control+Shift to create a symbolic link, or Alt to get the menu of possible actions. [Key or mouse button] 
Drag an item (left mouse button)
ROX-Filer User Manual
Key or mouse button