Global Rating System (GRS) is a broad term that can refer to various rating methodologies, below are the most popular use of the term.
Financial Global Rating System
* IMF country index www.imf.org
* S&P Global www.spglobal.com
* Vertiv www.vertiv.com
* Moodys www.moodys.com
Hotels Global Rating System
* Forbes Travel Guide www.forbestravelguide.com
* Hotels Digest www.hotelsdigest.org