The DC++ Wiki is intended to document DC++'s extensions to the protocols it uses so that other clients can take advantage of them as well. In documenting some of the extensions, it has become easier to document the protocols themselves and the clients and hubs that exist.
The Neo-Modus Direct Connect protocol (NMDC) that DC++ uses primarily is a proprietary one. All of the guides and attempts to document it are unofficial, reverse engineered from packet capturing (and debugging) the official Neo-Modus Visual Basic (VB) client connecting to the official VB hub and other (official) clients. Most of the resulting documentation is accurate, but not all of it is (and before changing those parts you must consider interoperability).