  The existence of "radio weak BL Lac objects" (RWBLs) has been an open
question, still unsolved, since the discovery that quasars could be radio-quiet
or radio-loud. Recently several groups identified RWBL candidates, mostly found
while searching for low energy counterparts of the unidentified/unassociated
gamma-ray sources listed in the Fermi catalogs. Confirming RWBLs is a
challenging task since they could be confused with white dwarfs (WDs) or weak
emission line quasars (WELQs) when there are not sufficient data to precisely
draw their broad band spectral energy distribution and their classification is
mainly based on a featureless optical spectra. Motivated by the recent
discovery that Fermi BL Lacs appear to have very peculiar mid-IR emission, we
show that it is possible to distinguish between WDs, WELQs and BL Lacs using
the [3.4]-[4.6]-[12]$\mu$m color-color plot built using the WISE magnitudes
when the optical spectrum is available. On the basis of this analysis, we
identify WISE J064459.38+603131 and WISE J141046.00+740511.2 as the first two
genuine RWBLs, both potentially associated with Fermi sources. Finally, to
strengthen our identification of these objects as true RWBLs, we present
multifrequency observations for these two candidates to show that their
spectral behavior is indeed consistent with those of the BL Lac population.
