For some reason CGC designates a difference in their pop report for their energy cards
Compulsion (Ext, S, Block) Much like Cephalid Coliseum above, Compulsion offers of the best "Jalum Tome" effects in the game of Magic
Graded Population Report: Mega Latias ex #100 Visualize the distrbution of grades in the chart
You get the convenience and excitement of an instant digital reveal, but the outcome is a physical, often graded, card that has actual value
The short answer is an ability which can add mana to your mana pool, and which doesnt have any targets
The practical implication: Japanese cards are generally easier to keep in pristine condition because the card stock is less prone to certain types of edge whitening that occur during the packaging and handling process