Selected lines of EtNCO. The grey areas indicate the observed spectra smoothed up to 3 km s⁻¹ for optimal line visualisation; while the red and blue lines represent the best LTE fit for the single EtNCO and all the other detected species, respectively. Blue labels indicate the detected species within each spectral range while the quantum numbers of each EtNCO line are indicated in red. See the text and Table 1 for more details.