These two visas work in sequence and are designed to allow a partner to come to Australia on the 309 temporary visa while a decision is made on the spouse 100 permanent visa. If the partners are married, the marriage must be valid under Australian law; if in a de facto relationship, the rules listed above must be observed.
As with the 309/100 visas, the 820/801 visas enable partners to be together temporarily, on the 820 visa, while a decision is made on the 801 permanent visa. Very similar conditions apply to both pairs of visas.