Grand Rapids Public Library?
Great Reformed Ping List.
Speaking as someone who went to school within walking distance of the main Grand Rapids Public Library building in downtown Grand Rapids, that's an amusing alternative acronym for the Great Reformed Ping List that I'd never thought of.
However, I don't think even back in the 1970s or early 1980s, when I was spending a lot of time in that library, that very many of the patrons of the Grand Rapids Public Library would have been mistaken for being confessional Calvinists. Grand Rapids has taken a serious wrong turn and did so several decades ago.