That means the overall card has a red and white colour identity, so can only be used with Commanders that have red and white in their colour identity (Boros, Mardu, Naya, or Jeskai)
Photos of uncut sheets, which are quite abundant for the WOTC era but rare for sets released by Nintendo/TPCI, give exact information on rarities of individual cards
This allows the player to pull Energy cards from other Pokmon, potentially powering Blastoise up for a massive Hydro Pump, or even saving an Energy card from being discarded before the defeat of another Pokmon
Other than specific cards that have "Trample Over Planeswalkers", you won't take any excess damage dealt to a Planeswalker
This is a simple but very effective combo lets you conveniently remove your entire deck from play to win on the spot with a Thassa's Oracle (which is also a merfolk!)
Excellent sealed collectible value