Deep CCD and near infrared imaging and photometry of
 flat spectrum radio sources from the 1 Jy sample
 show that nearly all members have an optical or
 infrared identification with a brightness closely
 proportional to the radio flux density (in agreement
 with identification programs for other flat spectrum
 radio samples).  There is one outstanding exception,
 which is far fainter than expected from this
 proportionality, and two additional objects which
 are very faint galaxies but whose nuclei may also
 be very faint. Because the other very faint optical
 identifications are obscured or have very red
 continua, it is possible that these three sources
 are just extreme examples of the same behavior;
 on the other hand, they might represent an
 optically (and infrared) quiet type of quasar.
 Because no other flat spectrum sources seem to
 be truly optical-infrared quiet, the latter
 possibility would imply discovery of a new
 emission mechanism or source geometry for quasars.
 Deep ISO imaging of these sources at 11.5 microns can
 tell if they are intrinsically faint in the infrared
 as well as in the optical.