The results of EPR and ENDOR investigations of N donors in various SiC polytypes are critically reviewed. It is discussed whether N donors can be understood as shallow donors with the EMT (Effective Mass) theory. It is shown that only in 3C SiC they are adequately described as being shallow and by EMT. The EPR spectra of P donors are reviewed and reinterpreted to be due to B donors on SIC sites in analogy to the findings of N donors following a recent suggestion by Greulich-Weber. A brief discussion of the Al accepters follows, which have shallow EMT character according to the present EPR data. Before discussing "shallow" B accepters, the characteristic features of the deep Sc accepters and their electronic structure is discussed. It is then shown that the shallow B accepters clearly have a deep defect character when reviewing the EPR and ENDOR data, albeit being at a rather shallow ionisation level. A common feature between Sc and B accepters is the fact that there are different EPR spectra and ionisation levels differing by a few meV depending on the localisation of the hole along the c-axis on other bond directions.