Fiducial PDS for different spectral states in the HID of Fig. 3. Bigger panels with pink stars show the main timing features observed in the NICER dataset: the NBOs in the NB (PDS #010001 of Obs-2), the FBOs in the transition from the NB to the FB (PDS #220701 of Obs-2), the isolated HBO near the HA (PDS #150500 of Obs-2), and the broad-band red noise observed in the FB (PDS #130401 of Obs-3). The two smaller panels with grey stars show less common and tentative features, such as the narrow QPOs discovered in the mid FB (PDS #010001 of Obs-1), or the pair NBO + HBO in the NB (PDS #040101 of Obs-3).