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.)