All references to files in the HTML are "relative" to the directory "tree". Using relative references means that the whole structure of files can be moved to any directory on any device accessable to the computer. In particular one could move the Tree from the CDROM on which it is distributed to the hard drive and then one could make "local" modifications to it.
There are bound to be errors/omissions. Please report any that you find to "email@example.com" Additonal information and/or photos would be appreciated by everyone who uses the Tree.