ps -f command showing process names with square brackets

[Ramki]

Hi,

I am using Tru64 Unix V5.1B with patch kit2.

When I give ps -ef command I am getting output like this for some of
the processes:
root 0 0 0.0 Aug 26 ?? 1:40.59 [proc1]

|____ Note
a square bracket here

Any idea, why the output is coming like this?

BTW, the man page for ps says like this:
-f Attempts to generate a full listing. Under certain
circumstances, the
-f option does not return the full path and arguments of a
process.
Instead, it will return a bracketed process name such as
[process_name]. This behavior conforms with the XPG4 standard.

Thanks in advance,
Ramki