possible domain status

WHMCS in his web interface offers some predefinied domain statuses:

active, pending, pending transfer, expired, transferred away, cancelled, fraud

The question is: writing a registrar module (and having so a way to set also different domain status), may I do it?

That's to say: i.e. may I set a domain in a "pending update" status ?

Or, even if that specific TLD has different statuses, I need to "convert" them to the nearest of the 7 statuses provided by WHMCS?

Or if I use any status different from whose provided, there's a way that other WHMCS authomatisms fall, and so using one of those seven statuses is mandatory?

I suspect the answer would be that if these custom statuses were purely for show, then yes you could add custom statuses - but there would be no functionality to them unless you coded it yourself.

those existing 7 statuses will trigger specific functions within WHMCS, a "pending update" status should do nothing by default.

it might be worth experimenting with, but i'd be inclined to stick with the default 7 statuses unless you have good reason to go beyond them.