you specify a URL, for example <a href="http://www.keil.com/pack/" target="_blank">http://www.keil.com/pack</a>, then you have to make the PDSC file and the corresponding Pack file(s) available for download at that exact location. The naming of the files follow the standard naming rules. For example, the ARM::CMSIS PDSC and Pack files are available here:<br/>
 <a href="http://www.keil.com/pack/ARM.CMSIS.pdsc" target="_blank">http://www.keil.com/pack/ARM.CMSIS.pdsc</a> and <br/>
 <a href="http://www.keil.com