Links between peaks can be visualized and adjusted interactively. If link display is turned on (use the Links checkbutton on the spectrum attributes Peak tab, or the "nv_win link" command), lines will be drawn connecting peaks that are linked. In the example below peak link display is on and one can see that the black peak (with assignment 31.HN) is linked to the magenta peak (numbered 9).

Peaks can be interactively linked on the spectrum display. First, ensure that the cursor is in the selection mode, and then select two peaks by clicking on the first, and shift-clicking on the second. Now use the Peaks - Link menu item from the Spectrum pop-up menu to link the selected peaks together. If link display is turned on you'll now see a line connecting the linked peaks. Remember that peak linking (or sharing of a common resonance) actually happens at the level of peak dimensions. The code invoked from the Peaks - Link menu item chooses only one dimension to link. This will be the dimension, chosen between that displayed on the x axis, and that on the y axis, with the minimum chemical shift difference between the two peaks. In the example below, where the two peaks on the left side of the spectrum are selected, the link will be formed between the HN dimensions of the peaks.

Links between peaks can be removed in a similar manner, just select the two peaks and choose the Peaks - Unlink menu item.