Ok good. Then how about having ASDF loudly announce that it is registering the default directory (e.g. ~/cl/), as well as providing the hint about using a .conf file with the right syntax with :tree, if the user wants to exclude certain subdirectories. 

The goal here is to make the addition of the default registry directory as painless and surprise-free as possible for anyone who already happens to have stuff floating around in the new default directory.