• Log to file or to daemon
• Fail gracefully - if so inclined
• Date & time, routine name, username
• Example: libimsl20.log

 
Wed_May_17_1995_08:49 L2TCG     filei
Wed_May_17_1995_08:49 LFSCG     filei
Fri_Jun_02_1995_16:54 QDAGS     mrgoers
Wed_Jun_07_1995_17:26 QDAGS     mrgoers
Wed_Jun_14_1995_15:57 LSGRR     ilu
Thu_Jun_15_1995_08:40 LSGRR     ilu
Thu_Jun_15_1995_08:47 LSGRR     ilu