Why do crond threads show as uppercase in ps output?

Issue

• Why do some formulations of ps show crond threads as upper-case in RHEL6? (The same will be all lower-case in RHEL5.) The following commands were run on RHEL 6.

[root@localhost ~]# cron=$(</var/run/crond.pid)

[root@localhost ~]# pstree -pa | grep -A6 $cron
  |-crond,10964
  |   |-crond,30684
  |   |   `-crontest,30686 /root/crontest
  |   |       `-sleep,30687 30m
  |   |-crond,30722
  |   |   `-crontest,30724 /root/crontest
  |   |       `-sleep,30725 30m

[root@localhost ~]# ps --ppid $cron --pid $cron
  PID TTY          TIME CMD
10964 ?        00:00:04 crond
30684 ?        00:00:00 crond
30722 ?        00:00:00 crond

[root@localhost ~]# ps -f --ppid $cron --pid $cron
UID        PID  PPID  C STIME TTY          TIME CMD
root     10964     1  0 Aug14 ?        00:00:04 crond
root     30684 10964  0 20:48 ?        00:00:00 CROND
root     30722 10964  0 20:49 ?        00:00:00 CROND

[root@localhost ~]# ps f --ppid $cron --pid $cron
  PID TTY      STAT   TIME COMMAND
10964 ?        Ss     0:04 crond
30684 ?        S      0:00  \_ CROND
30722 ?        S      0:00  \_ CROND