Modules are loosely defined by their corresponding entry in the config file. 

They are also sorted in the same sequence (which is done by the machine, not by content).

Note that individual config options are often explained inside the config section of the log file.

Config file modules that just define files/directories are, as a tendency, not explained here.

Maintainers are mentioned as far as possible, but they are not responsible for answering arbitrary service requests.