(7)For the purposes of permission to use the advanced CVA method for a limited number of smaller portfolios, it is appropriate to consider a portfolio as a netting set as defined in Article 272(4) of Regulation (EU) No 575/2013 the number of non-internal model method (‘IMM’) transactions subject to the CVA risk charge and the size of non-IMM netting sets subject to the CVA risk charge, and to limit them in terms of a percentage of the total number of all transactions subject to the CVA risk charge and a percentage of the total size of all netting sets subject to the calculation of CVA risk charge, in order to take account of the different dimensions of institutions.