It is trivially known that the complement of a symmetric balanced incomplete block (SBIB) design is again an SBIB design. While charactering all the SBIB designs, Mohan, Kageyama and Nair  have obtained a new classification of these SBIB designs. It is found that this classification has a specific impact on the complements of these SBIB designs. This has been explored in this paper in the light of . In addition, at the end, these designs along with their other properties have been tabulated for the ready reference and for practical purposes.