I've got nothing substantive to add, but wanted to note that, in the U.S. and Canada, and perhaps other regions, the de facto standard for technical specifications for construction projects (CSI and CSC) uses 7 levels. I'm no longer working on these kinds of docs, but I could see how Greg's code could come in handy to those who do, and are working on specs coming in from outside firms/vendors that need to be quickly and consistently formatted.