"Giants" was one of the only team nicknames used with any frequency at all in 1886 newspaper writeups, and the only team nickname, "period," found in Spalding's Official Guide for 1889. However, the team's official name, as printed on its scorecards, remained simply the New York Base Ball Club. Although the "Giants" nickname was well established, it wasn't endorsed by the franchise until they put it on the home programs for the 1911 World Series; the prosaic "NEW YORK" or simple block letters "NY" were used on uniform shirts until 1918 when "GIANTS" first appeared. (Okkonen)