  We discuss the origin of strong crustal magnetic field in one of central
compact objects (CCOs) --- a neutron star PSR J1852+0040 in the supernova
remnant Kes 79. Taking into account its relatively long present day spin period
we conclude that the field could not be generated via a dynamo mechanism. If
this neutron star indeed is a magnetar with field submerged during a strong
fall-back episode, then it argues against the dynamo field origin in magnetars.
Otherwise, Kes 79 is not a close relative of normal magnetars. A discovery of
an anti-magnetar with a millisecond period and strong crustal field
identifiable, for example, due to large pulse fraction, would be the proof of
the dynamo field origin. Existence of such sources is in correspondence with
the present standard picture of neutron star unification. However, the fraction
of magnetars with submerged fields can be small --- few percent of the total
number of CCOs.
