[Zope] Accessing built in Icons

Does anybody know how to access the icons that Zope uses for its objects (folders, DTML Documents, etc.) for a Z Class I created, or where that info might be found? I know I could just load the icon image from the "lib/python/Products/OFSP/images" directory, but I'm trying to figure out how to do it without using up extra space in the database for that image (assuming that I'm not misunderstanding that bit...) (No... in the long run, it probably doesn't matter for such small images, and usually I'd just make my own image anyway, but it'll give me a slightly better idea of Zope's structure and this particular class isn't enough to bother with a new icon.) - Gregor