It signifies that the card has a reverse holographic pattern on the back. This pattern is usually shiny and iridescent, adding a special effect to the card.
Not all Pokemon cards have a reverse holo pattern. Only certain sets and card rarities feature reverse holo versions.
Here's how you can tell if a Pokemon card is a Reverse Holo:
* Look at the back of the card. If it has a shiny, iridescent pattern, it's a Reverse Holo.
* Check the bottom right corner of the card. The reverse holo symbol (a diamond with a star inside) will be present.
* Check the card's rarity. Reverse holo cards are often, but not always, more rare than standard cards.
Reverse holo cards are generally considered more valuable than regular non-holo cards.