What does SMS stand for on a Kennedy half dollar?

Answer 1

The letters SMS stand for Special Mint Set, but they should be on the package the coins came in and not on the coin itself.

During 1964-65 the Mint was under tremendous pressure to make as many clad coins as possible to replace the billions of silver coins that were being hoarded and melted. Mint marks were eliminated so that coins could be made in any quantity anywhere without creating "instant rarities" and presses normally reserved for making proof coins were diverted to making regular circulation strikes.

At the same time a number of politicians erroneously blamed numismatists rather than hoarders for the coin shortage, which produced a lot of opposition from the numismatic community. In an effort to defuse a bit of the anger the Mint agreed to make Special Mint Sets containing coins that were not quite proof quality but were still better than standard circulation pieces.