One use of the configuration is to simply record what a system is. This documentation could in turn become quite extensive, thus complicating the data model. It is important to distinguish between configuration data and descriptive data. Of course comments can be applied at any level, even in most tools, however the bloating of the data can reduce its usefulness. For example, the system configuration is not a place to record historical changes, or descriptions of design and intent for the various elements. The configuration data is simply to be "what it is" or "what we want it to be".
