Exceptionally clear images of intramolecular structure can be attained in dynamic force microscopy (DFM) through the combination of a passivated tip apex and operation in what has become known as the "Pauli exclusion regime" of the tip-sample interaction. We discuss, from an experimentalist's perspective, a number of aspects of the exclusion principle which underpin this ability to achieve submolecular resolution. Our particular focus is on the origins, history and interpretation of Pauli's principle in the context of interatomic and intermolecular interactions.