Select inside marquee window
Create a toggle-able feature like the one found in many CAD programs:
Select ONLY the objects ENTIRELY inside the selection window marquee via the following methods:
1. hold Shift+drag
2. Dragging left-to-right enables "select inside", dragging right-to-left enables "select touching" (as per most CAD programs)
Yes, this is a must have for a professional app.
What Haveyou commented
I agree that this basic feature is essential, but I don't agree that any modifier keys or specific dragging directions should be required. Shift-drag is already used to add to the selection. so that won't work.
This should be a selectable selection mode, and in fact it should be the default.