B.A.T.M.A.N. (better approach to mobile ad-hoc networking) is a routing protocol for multi-hop ad-hoc mesh networks. The networks may be wired or wireless. See http://www.open-mesh.org/ for more information and user space tools.
This is an option for use by developers; most people should say N here. This enables compilation of support for outputting debugging information to the kernel log. The output is controlled via the module parameter debug.