Hi all, thanks for your explications and addition; it's OK now. A special thankyou goes to utiler! Please excuse me for the expression vaporfile, I'm sorry! Bert

Ah, I see, you meant for plan views, like AutoCAD does. That would be a tricky one to implement as as soon as you orbited out of the plan view the re-aligned selection box would become more of a hindrance than a help. An effective workaround is to save a scene which is a rotated plan view of the skewed bit of the overall plan which you can switch to and then pan around when you need to make a selection.