Pokemon Black Star Promo Single Cards have a star that indicates that they are promotional. The five-pointed black star has the word "PROMO" written across it in white ink.
The first promotional set consisted of 53 cards in all with a 54th being a holographic Ancient Mew, the 53 Promo Cards vary between holographic and normal and encompass Pokemon and Trainer cards alike. The second promotional set, called Best of Game, was also released by Wizards of the Coast. It included reverse holographic reprints of Hitmonchan and Electabuzz from the Base Set, Rocket's Hitmonchan and Rocket's Mewtwo from Gym Challenge, and Professor Elm from Neo Genesis. In addition, there were four new cards: Rocket's Sneasel and Rocket's Scizor from the Pokémon*VS Japanese expansion; and Dark Ivysaur and Dark Venusaur from the Pokemon Web Japanese expansion.
Under Nintendo's publishing house, the third promotional set consisted of 40 cards. The release of these cards coincided with the Pokemon Organized Play packs, and as a result, are less well documented. The fourth promotional set, also under Nintendo, has been running since the release of Diamond & Pearl Base Set, and are better marketed by Pokémon USA, Inc. The most famous of these is the card "Birthday Pikachu"
Pokemon Black Star Promo Single Cards - Pokemon Cards