The CH class record stores the chaosnet host id that corresponds to the dns entry. Chaosnet didn't use IP addresses (which are specific to the internet protocol

The CH class record stores the chaosnet host id that corresponds to the dns entry. Chaosnet didn't use IP addresses (which are specific to the internet protocol) to identify hosts - it used a 16 bit number composed of an 8 bit subnet ID and a 8 bit subnet-local host ID. When querying the DNS you specify the class of address you want (IN, CH, whatever) and the resolver returns you the corresponding record. So if a host has a connection to an IP network and an Chaosnet network then it would have two entwork identities and its DNS zone would contain both classes of ID. Obviously IN is really the only network class that is used now, but these things persist in old code.