Results from the spectral classification of the donor star in YY Dra using the optimal subtraction technique with the subsolar templates listed in Table 3 (squares) and the supersolar templates from Table 4 (triangles). The top panel shows the results for the full average spectrum of YY Dra, while the middle and bottom panels are for the averages at orbital phases 0.9 − 0.1 and 0.4 − 0.6, respectively. The relation between spectral type and effective temperature is illustrated at the top.