2009/1/6 Grabovský Matěj 65s.mg@atlas.cz:
The , command enforces that the formula will be *always* rendered with TeX.
Actually, it doesn't, , is just a space which can be rendered in HTML, just not simply. If you have your preferences set to always use HTML where possible, even if it's a mess, you'll get \phi, in HTML, by default you only get HTML where it's simple. To force PNG in all cases, you need something like /,/! (a space followed by a negative space) which can't be done in HTML.