  We are compiling a new list of gamma-ray jetted active galactic nuclei (AGN),
starting from the fourth catalog of point sources of the Fermi Large Area
Telescope (LAT). Our aim is to prepare a list of jetted AGN with known
redshifts and classifications to be used to calibrate jet power. We searched in
the available literature for all the published optical spectra and
multiwavelength studies useful to characterize the sources. We found new,
missed, or even forgotten information leading to a substantial change in the
redshift values and classification of many sources. We present here the
preliminary results of this analysis and some statistics based on the gamma-ray
sources with right ascension within the interval $0^{\rm h}-12^{\rm h}$
(J2000). Although flat-spectrum radio quasars and BL Lac objects are still the
dominant populations, there is a significant increase in the number of other
objects, such as misaligned AGN, narrow-line Seyfert 1 galaxies, and Seyfert
galaxies. We also introduced two new classes of objects: changing-look AGN and
ambiguous sources. About one third of the sources remain unclassified.
