I think it's interesting to note that IE 9, Firefox 9, and Chrome 16 all render the lines differently. Firefox places them at a position that would be underneath text, if text were present along with the image. Chrome puts them above the image. IE puts them above the image, but then erases one text line's worth of space above the line (see the info links on the left of all the Announcements entries on the main page).
I'm not much of a CSS expert, but this seems to indicate that whatever is being used to get the lines in the first place, it's something that just about nobody else is doing, because if it were common, I can't see having completely different rendering on the three top browsers.
I'm not much of a CSS expert, but this seems to indicate that whatever is being used to get the lines in the first place, it's something that just about nobody else is doing, because if it were common, I can't see having completely different rendering on the three top browsers.