Configure short tag endings

I know that in VS there is a config setting that when a control is dropped on a page from the toolbox it will format with a short closing tag instead of a long one. IE <asp:Texbox ............. /> instead of <asp:Textbox .................. ></asp:Textbox>
but I canot seem to find it anywhere in the menus. Can someone tell me where it is please?
Thanks
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