Why don't you ask your client? If they instruct you so, they definitely know how to do that. It is ok that a client giving a task for you also explains how to achieve it.
He does not know, his company does not use Trados. He just said some translarors do it, but after Paul's answer I think he was just confused how Trados works.
He does not know, his company does not use Trados. He just said some translarors do it, but after Paul's answer I think he was just confused how Trados works.