Internationally, he is best known today for his development of the system now known as Rexed laminae, but in Sweden, he is also known for his involvement in the "du-reformen" of the Swedish language.
The beginning of the du-reformen is associated with Bror Rexed, the then head of the National Board of Health and Welfare (Socialstyrelsen), who in his welcome speech to the staff in 1967 announced that he would address everyone as du, increasing the effects of the reform and bringing it to a more frequent use.