What exactly is the purpose of this feature and does the PO have to have your TER ID ?
You can find this any time by clicking the Site Map link at the bottom of any page. Then look for "White List FAQ's" and click it.
White List (aka White List Referral) is given by a provider. They need your TER handle (they can search by your e-mail if they have the e-mail you joined TER with) in order to give the White List.
For all intents and purposes your TER ID is your TER handle. You do have a number but it isn't used for anything. Providers have a TER ID number and it can be used to identify them and locate their profile.
they don't bother to screen any further. They do insist that you have PM so that they can be sure the client is the person he says he is.
Other gals don't trust the WL at all