(28)In the assessment of the process of assignment of exposures to exposure classes, specific requirements should be laid down for the verification by the competent authorities for the assignment of exposures to retail exposures because of their preferential treatment in terms of risk-weighted exposure amounts calculation. Some exposure classes are defined on the basis of the characteristics of the transaction and others on the basis of the type of obligor; as a result, there may be exposures that fulfil the criteria of more than one exposure class. Competent authorities should therefore verify that the institution applies the correct sequencing of classification in order to ensure a consistent and unequivocal assignment of exposures to exposure classes.