This catalog is a compilation of stars that have been suspected of variability but have (mostly) not been finally designated as variables. It is the merging and latest updated version of the compilation of the New Catalog of Suspected Variable Stars (NSV Catalog) originally published in 1982 by Kukarkin et al. and the Supplement to the NSV originally published in 1998 by Kazarovets et al. This version (NSV Release 2) has updated the previous catalog in several ways. The accuracy of coordinates has been drastically improved for the objects in the catalog; for most of them, the authors have revised the photometric and spectroscopic data and updated the remarks. In the cases with no existing finding charts, the authors recovered variability of 2800 stars of the catalog, despite large errors of the previously published coordinates. The data contained in the present catalog include positions, magnitudes, variability types, references to the literature, and spectra. This version of the GCVS catalog was last updated by the HEASARC in September 2022, based on the files <a href="http://www.sai.msu.su/gcvs/gcvs/nsv2/nsv2.txt">http://www.sai.msu.su/gcvs/gcvs/nsv2/nsv2.txt</a>; and <a href="http://www.sai.msu.su/gcvs/gcvs/nsvsup/nsvs.dat">http://www.sai.msu.su/gcvs/gcvs/nsvsup/nsvs.dat</a>;. This is a service provided by NASA HEASARC .