None, really, though you can embed many MiniVend tags inside of regular HTML with things like:
<A HREF="[href minivend_page]">Link</A> <SCRIPT LANGUAGE=MV MV="set Action"> mv_todo=return mv_nextpage=your_page </SCRIPT>
In most cases you will have to edit MiniVend pages by hand.
(MiniVend 3.09 is the first version to allow tags to be embedded within regular HTML.)