There are several log/debug facilities available (the latest list you can see in sources Debug.cc/Debug.h):
#define LOG_TACACS 1 // tacacs+ protocol events
#define LOG_BILLING 2 // billing subsytem
#define LOG_AAA 3 // AAA
#define LOG_DB 4 // database system activity
#define LOG_SNMP 5 // snmp system activity
#define LOG_NETFLOW 6 // netflow collector
#define LOG_SERVER 7 // tcp/udp server
#define LOG_CC 8 // cryptocard
#define LOG_POOL 9 // address pool system
#define LOG_TRACK 10 // user track system
#define LOG_HTTP 11 // http interface
#define LOG_TIP 12 // bundle protocol
#define LOG_TEP 13 // external protocol
#define LOG_ERROR 0
// log NetFlow
#define LOG_NETFLOWLOG 252
// log events
#define LOG_EVENT 253
// log informational
#define LOG_INFORM 254
// log logging information to other file
#define LOG_LOGGING 255