Here are the data structures with brief descriptions:

C_vector
Cbuffer
Cbuffer_data
Ccmd_element	Structure of a command element
Ccmd_node	Node which has some commands and prompt string and configuration function pointer
Cdesc	Command description structure
Chost	Host configuration variable
Ctelnet_connection	A telnet connection
Cvty
Cvty_app_info
Cvty_out_context
Cvty_signal_data