Verbatim from the common/send.c:
(void)sprintf(linebuf, "%c %d %d %s %s %s %s %d %s %lu %llu %lu %llu", /* exit code as defined in common/struct_def.h; some common: * '0' normal exit, '-' unregistered client quit, 'k' k-lined, * 'K' killed, 'X' x-lined, 'Y' max clients limit of Y-line, * 'L' local @host limit, 'l' local user@host limit, 'P' ping * timeout, 'Q' send queue exceeded, 'E' socket error */ cptr->exitc, /* signon unix time */ (u_int) cptr->firsttime, /* signoff unix time */ (u_int) timeofday, /* username (if ident is not working, it's from USER cmd) */ username, /* hmm, let me take an educated guess... a hostname? */ hostname, /* ident, if available */ cptr->auth ? cptr->auth : "", /* client IP */ cptr->user ? cptr->user->sip : #ifdef INET6 inetntop(AF_INET6, (char *)&cptr->ip, mydummy, MYDUMMY_SIZE), #else inetntoa((char *)&cptr->ip), #endif /* client (remote) port */ cptr->port, /* server sockhost (IP plus port or unix socket path) */ cptr->acpt ? cptr->acpt->sockhost : "?", /* messages and bytes sent to client */ cptr->sendM, cptr->sendB, /* messages and bytes received from client */ cptr->receiveM, cptr->receiveB);