We have observed pseudodoublets representing a partly resolved fine structure of rovibronic lines in the visible part of the D2 emission spectrum. They are characterized by splitting values of about 0.2 cm−1 and relative intensity of the doublet components close to 2.0. It is shown that they are determined by triplet splitting in lower rovibronic levels of various 3LAMBDAg± - c3PIu electronic transitions. It is proposed to use the existence of such partly resolved fine-structure patterns for identification of numerous unassigned spectral lines of the D2 molecule coming from a great variety of triplet “gerade” electronic states to vibrorotational levels of the c3PIu state.