I'm not sure what being whitelisted is...  is it having a provider on TER giving you a referral?

Sometimes a lady will just do it on her own, but you can also ask.  Same consider it taboo to ask, but it can be helpful in opening some doors especially when you are new so IMHO, go ahead and ask.

Some providers simply do not provide them, so keep that in mind as well.  The answer may be "no and it   is not personal"

an ok that other providers can see and know you are ok to see.  It's like a ref on DC or an OK on P411.

Swim