Save time and money by buying year sets. It's the easy way to fill gaps in your collection – and most sets feature savings compared to ordering each stamp individually! Year sets without a suffix have the most popular and affordable commemorative stamps issued that year. Year sets with an "A" suffix contain all commemorative and definitive stamps issued that year. "C" year sets contain all commemorative stamps issued that year. "D" contains all definitive stamps issued. See individual item descriptions for the exact contents of each offer.