Defines starting with `c' in netccitt

• CALL netccitt/pk.h:180
• CALL_ACCEPTED netccitt/pk.h:181
• CCITTPROTO_HDLC netccitt/x25.h:53
• CCITTPROTO_X25 netccitt/x25.h:54
• CLEAR netccitt/pk.h:182
• CLEAR_CONF netccitt/pk.h:183