Thanks Derek, but this is not exactly what I'm looking for. What I can remember is that on that page, maybe referenced from the link I provided, there are examples on different picture symbols and we could get the URL information. For example, I have below codes to represent a work location and I got the URL from that page.
workSymbol = new esri.symbol.PictureMarkerSymbol({"angle":0,"xoffset":0,"yoffset":0,"type":"esriPMS","url":"http://static.arcgis.com/images/Symbols/PeoplePlaces/Office.png","contentType":"image/png","width":18,"height":18});
Same content is now here: http://developers.arcgis.com/en/javascript/jshelp/inside_renderers.html