{section: Usage}
 
+{subsubsection: Starting up}
+
 Start your program like so:
 
 {code}
 setarch x86_64 -L -B -R ./a.out -_condor_ckpt ckpt
 {endcode}
 
+Replace a.out with your program name.
+
 Replace "x86_64" with "i386" if you're on a 32-bit system.  You may be able to omit the -B and associated 32-bit memory limit under unknown circumstances.  You can add arguments to the program itself before or after the arguments above.
 
-To checkpoint and exit, send SIGTSTP.  To checkpoing and continue, send SIGUSR2.
+Replace ckpt with the file name you want your checkpoint written into.  You can omit all of the arguments, in which case the checkpoint file is your program name with .ckpt appended.
+
+{subsubsection: Checkpointing}
+
+To checkpoint and exit, send SIGTSTP.  To checkpoint and continue, send SIGUSR2.
+
+Checkpoints should be atomic; they are written to ckpt.tmp and moved to ckpt upon completion.
+
+{subsubsection: Resuming a checkpoint}
 
 To resume from a checkpoint, do this: