'Allow changing of processes' option on a status

Hello,

I;m looking at adding a 'Reinitialise' action to a new process and the recommendation is that I set the 'Allow changing of processes' option on the status containing the new action.

I can't see this option available on the status - am I missing something obvious?

I've Googled as much as I can without an answer so far,

many thanks,

Keiron.