In the context of quantum mechanics and atomic structure, the principal quantum number (n) indicates the energy level of an electron in an atom. For the 4th principal level, n is equal to 4. The sublevel designation provides further detail about the shape and type of orbitals present. In this case, the f sublevel is specified, which corresponds to a set of orbitals characterized by their complex shapes and the ability to hold a maximum of 14 electrons.

Thus, when identifying the orbitals in the 4th principal level and f sublevel, we refer to the 4f orbitals. The notation indicates that these orbitals are part of the fourth energy level and belong to the f sublevel, confirming that the correct identification is indeed the 4f set of orbitals.