By now you must have come across the acronym PPOR. This stands for Principal Place of Residence. There is also the term Main Residence. How do they differ? Main Residence is the new term in the new income tax act - ITAA97 or Income Tax and Assessment Act 1997. Up until the new act the Commonwealth law referred to the main residence as the PPOR. This was changed when the new act came into play. The meaning is essentially the same though. However with land tax this is state based legislation and most states still refer to the main residence as the PPOR in their Land Tax Acts. e.g. in Victoria see s56 http://www5.austlii.edu.au/au/legis/vic/consol_act/lta200590/s56.html therefore strictly speaking when referring to income tax (including CGT) we should be referring to the Main Residence and when referring to land tax we should be referring to the Principal Place of Residence.