Splitting implies that an entity that was previously one or uniform gets divided into two or more pieces. Whereas splitting wood is readily understood, the unexpected complexity of splitting in the context of NMR spectra becomes evident when considering the relationship of peaks and lines (Figure ): a shoulder, as is visible between peaks 2 and 3 in Figure , can be split by, e.g., applying a window function that enhances spectral resolution. In this process, it is difficult to say whether peak 2 or 3 or another unknown/unassigned peak is split. However, this situation resolves when we consider the underlying lines: as also shown in Figure , the intensities and frequencies/locations of lines 2, 3, and 4 explain why the pattern of the overlapping resonances of the two hydrogens contains the shoulder at the peak level and fully splits at the line level of interpretation. This shows that precise nomenclature does not represent a form of the proverbial splitting of hairs, but is rather essential for NMR data interpretation.