The atoms in the 2D chemical structures can be assigned to the chemical shifts. Assign atoms by following the next steps:
Select the atoms and shifts you want to assign with Ctrl + left mouse, right click selected atom and select Assign from the popup menu.
Clear assignments by right clicking the atom or shift you want clear and select Clear Assignments from the popup menu.
The assigned atom and shift pairs are highlighted when one them is selected or hovered. J-Couplings are shown over the atoms when the coupled shifts are also assigned.
Assignments can be saved by selecting File → Save Atom Assignments. The assignments are also automatically saved when saving parameter file.
Hydrogens can also be assigned by showing them first. Show/hide hydrogens by right clicking an atom and select Add Hs or Remove Hs from the popup menu.