In UNIX, what are the Ss, Sl, and Ssl proccess types I see with ps aux?

Question

When doing a ps aux command, I see some process listed as Ss, Ssl and Sl.

What do these mean?

root     24653  0.0  0.0   2256     8 ?        Ss   Apr12   0:00 /bin/bash -c /usr/bin/python /var/python/report_watchman.py 
root     24654  0.0  0.0  74412    88 ?        Sl   Apr12   0:01 /usr/bin/python /var/python/report_watchman.py
root     21976  0.0  0.0   2256     8 ?        Ss   Apr14   0:00 /bin/bash -c /usr/bin/python /var/python/report_watchman.py 
root     21977  0.0  0.0  73628    88 ?        Sl   Apr14   0:01 /usr/bin/python /var/python/report_watchman.py

Solution

From the ps manpage:

   S    Interruptible sleep (waiting for an event to complete)

  For BSD formats and when the stat keyword is used, additional
  characters may be displayed:
  s    is a session leader
  l    is multi-threaded (using CLONE_THREAD, like NPTL pthreads do)

Comments

[LF00]

ps aux output meaning

[squircle]

When in doubt, man!

[Prado]

A 10 years old question, but since it is the first google result for this question, I am updating the URL link for for the ps manpage: freebsd.org/cgi/man.cgi?ps