The spectral lines whose identification and wave numbers were acknowledged to be dubious in a statistical analysis of all the experimental data on the triplet rovibronic transitions of the D₂ molecule published by now were studied. The capillary-arc discharge spectrum in a D₂-H ₂ (9: 1) mixture was measured at p ≈ 6 torr and current density j ≈ 10 A/cm². The wave numbers of 123 lines (of a total of 138 dubious lines) situated in the spectral region accessible to us (430-730 nm) were determined. The error in wave numbers was ≈ 0.06 cm^-1 because of the low intensity of the lines under study and overlap of their contours resulting from fortuitous superpositions of closely lying lines of other band systems (the so-called blending effect). The new wave number values were substantially different from the literature data. These differences were largely caused by random counting and blending errors and, in four instances, erroneous identification of lines in previous works.