248 Chapter 6 · Defense-in-depth Documentation Conventional wisdom holds that publishing all documentation centrally and online for the access of all is the best course of action.This can be a fatal error if taken too literally. If the policies and procedures are only available online, and that site becomes unavailable due to virus outbreak or some other DoS situation, then the documentation may as well not exist. It is necessary for all documentation to be centrally maintained and accessible by all. A solid practice involves maintaining the documentation in three places.Two are physical notebooks, one for original documents the other to be a working copy where pen and ink changes can be made before being made official in the master notebook.The third place to keep a copy is online, for maximum accessibility during routine operations. Careful consideration should be taken when deciding what goes into the documenta- tion, organization is very important. A good model is organized as follows: 1-0 Overview 1-1 Graphical High Level View 1-2 AV Program visual design (line and block chart) 2-0 Network 2-1 Network Map 2-2 Network Naming Convention 2-3 e-mail Servers (names, type, physical location) 3-0 Policies and Procedures