iptables chain name

vim iptables/iptables-1.4.10/libiptc/libiptc.c +59 
static const char *hooknames[] = {
     [HOOK_PRE_ROUTING]  = "PREROUTING",
     [HOOK_LOCAL_IN]     = "INPUT",                                                                         
     [HOOK_FORWARD]      = "FORWARD",
     [HOOK_LOCAL_OUT]    = "OUTPUT",
     [HOOK_POST_ROUTING] = "POSTROUTING",
 #ifdef HOOK_DROPPING
     [HOOK_DROPPING]     = "DROPPING"
 #endif
   };