Marquee selection in an orthographic view selects all bsp brushes in level, even if they are not under the marquee selection.
1. Open Editor (any project)
2. Create multiple bsp brushes within the viewport by going to placement mode>BSP.
3. In an orthographic viewport, marquee select (lmb and drag) around 1-2 bsp brushes, make sure some bsp brushes are not within the marquee selection.
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