Need explanation of 'who -d' output

Can someone tell me what the output of 'who -d' is ?

What's causing the process in the list to be there ?

What can be done to get rid of / fix those process ?

Are those process simple problems, important or urgent onces ?

I am asking because while looking for another 'who' option, I saw that '-d' one and when I tried it it listed close to 50 process in it on a server that has been rebooted less then one month ago. From a Google search I see that they are somekind of dead process left from init/users (???) but do not fully understand what they are, where they come from, if they are normal and what can be done about them.

Thought: I believe that "orphaned" processes (parent exits without collecting their return status) are picked up by init. It looks like init keeps a record of the processes that it inherits, and their eventual exit status.

If this is what "who -d" is displaying, then the processes have already gone. I have some on my AIX systems as well, so they are probably normal.

-d
Displays all processes that have expired without being regenerated by init. The exit field appears for dead processes and contains the termination and exit values (as returned by wait) of the dead process. (This flag is useful for determining why a process ended by looking at the error number returned by the application.)

I think that answers all the questions. They can't be fixed, as the processes have already ended. Perhaps they are set to 'once' in /etc/inittab.