Here is what the output of “launchctl list” means:

list [-x] [label]
          With no arguments, list all of the jobs loaded into launchd in
          three columns. The first column displays the PID of the job if
          it is running.  The second column displays the last exit status
          of the job. If the number in this column is negative, it repre-
          sents the negative of the signal which killed the job.  Thus,
          "-15" would indicate that the job was terminated with SIGTERM.
          The third column is the job's label.

So when you run “launchctl list | grep something”, the columns correspond to:
1. PID (if it’s running)
2. last exit status code
3. process name

Ref: http://developer.apple.com/library/mac/#documentation/Darwin/Reference/Manpages/man1/launchctl.1.html