On Mon, 12 Jan 2009 12:23:34 -0500, Mark J. Reed <[log in to unmask]> 

>Even over here in the US this use of "proper" still has some currency
>in technical jargon;  I would not at all be surprised to see "proper
>vector"/"proper value" used that way in an American mathematics paper.
> But in everyday English it can never mean "own".  For that we use
>various forms of the related word "proprietary".

Thanks, Mark, and Larry.

What about a teacher telling a class,
"Everyone get back to your proper seat!"
"Everyone get back to your own seat!"

IME the first choice is (was? four decades ago?) typically British.

Is it no longer?