S&P Global Ratings assigned its 'AAA' rating to Watertown, Mass.' series 2019 general obligation (GO) municipal-purpose-loan bonds and affirmed its 'AAA' rating on the town's existing GO debt. The outlook is stable. The town's full-faith-and-credit pledge, subject to Proposition 2-1/2 limitations, secures the bonds. We rate the limited-tax GO debt based on the application of our "Issue Credit Ratings Linked To U.S. Public Finance Obligors? Creditworthiness" criteria (published Jan. 22, 2018, on RatingsDirect). We are rating the obligation at the same level with our view of Watertown's general creditworthiness. Any limitation imposed on the obligor's ability to raise revenue is factored into the rating analysis. Therefore, we are not making a rating distinction. Officials plan to use series 2019 bond