  The scarce optical variability studies in spectrally classified Type 2 active
galactic nuclei (AGNs) have led to the discovery of anomalous objects that are
incompatible with the simplest unified models (UM). This paper focuses on the
exploration of different variability features that allows to separate between
obscured, Type 2 AGNs, and the variable, unobscured Type 1s. We analyse
systematically the Zwicky Transient Facility, 2.5 years long light curves of ~
15000 AGNs from the Sloan Digital Sky Survey Data Release 16, which are
generally considered Type 2s due to the absence of strong broad emission lines
(BELs). Consistently with the expectations from the UM, the variability
features are distributed differently for distinct populations, with spectrally
classified weak Type 1s showing 1 order of magnitude larger variances than the
Type 2s. We find that the parameters given by the damped random walk model
leads to broader H{\alpha} equivalent width for objects with {\tau}_g > 16 d
and long term structure function SF{\infty},g> 0.07 mag. By limiting the
variability features, we find that ~ 11 per cent of Type 2 sources show
evidence for optical variations. A detailed spectral analysis of the most
variable sources (~1 per cent of the Type 2 sample) leads to the discovery of
misclassified Type 1s with weak BELs and changing-state candidates. This work
presents one of the largest systematic investigations of Type 2 AGN optical
variability to date, in preparation for future large photometric surveys.
