google maps v3 standard icon/shadow names (equiv. of G_DEFAULT_ICON in v2)

I'm switching icon types of google maps markers between a default one and another one (made by google chart api). To switch back to standard icon I use: ``` marker.setIcon('http://maps.google.com/mapfiles/marker.png'); ``` For another icon I use: ``` marker.setIcon('http://maps.google.com/mapfiles/marker_yellow.png'); ``` The question is: is the URL I use really the "standard" (canonical)? Is it assured that google will not change it? it would be better to use some constant like `G_DEFAULT_ICON` in gmaps api v2. Is there anything similar in api v3? if not, where one can find the list of canonical icon/shadow URLs that are assured to work during all the google api v3 life? The same question for shadows - when I set the icon, how to get the standard shadow instead of using ugly `m.setShadow(new google.maps.MarkerImage('http://maps.gstatic.com/mapfiles/shadow50.png', null, null, new google.maps.Point(10, 34)))`? (Note that `getShadow()` will not tell you anything as it returns `null` on the default icon with defaultshadow). PS: there are some dynamic icons APIs but they all are now deprecated, and no remedy has been found.