Just to give you a rudimentary understanding, a runtime folder contains all the subfolders and files which are associated to content in your Poser Library. As an example, I screencaptured Poser's Download runtime from my Poser 11 Pro content folder which is entirely empty of content. I have my own external runtimes and do not use this particular location. Notice the path at highlight 1 which shows the typical subfolder breakdown of any content runtime. The Downloads folder is the primary, or parent, folder that contains a runtime subfolder and subsequently another subfolder called libraries. The Libraries folder contains a series of subfolders that appear in your Poser Library, as illustrated in highlight 2. This is the base structure of any content folder regardless of it's name, as long as there is a folder called runtime within it.