Only a face-up ongoing scheme card may be abandoned, and only during an Archenemy game. See rule 314, “Schemes,” and rule 904, “Archenemy.”
July 3, 2020 · Core Set 2021
“Bolster N” means “Choose a creature you control with the least toughness or tied for least toughness among creatures you control. Put N +1/+1 counters on that creature.”
May 3, 2019 · War of the Spark
To manifest a card, turn it face down. It becomes a 2/2 face-down creature card with no text, no name, no subtypes, and no mana cost. Put that card onto the battlefield face down. That permanent is a manifested permanent as long as it remains face down. The effect defining its characteristics works while the card is face down and ends when it’s turned face up.
January 25, 2019 · Ravnica Allegiance
To manifest a card, turn it face down. It becomes a 2/2 face-down creature card with no text, no name, no subtypes, and no mana cost. Put that card onto the battlefield face down. That permanent is a manifested permanent as long as it remains face down. The effect defining its characteristics works while the card is face down and ends when it's turned face up.
April 27, 2018 · Dominaria
To manifest a card, turn it face down. It becomes a 2/2 face-down creature card with no text, no name, no subtypes, and no mana cost. Put that card onto the battlefield face down. That permanent is a manifested permanent as long as it remains face down. The effect defining its characteristics works while the card is face down and ends when it’s turned face up.
September 30, 2016 · Kaladesh
“Support N” on a permanent means “Put a +1/+1 counter on each of up to N other target creatures.” “Support N” on an instant or sorcery spell means “Put a +1/+1 counter on each of up to N target creatures.”
April 8, 2016 · Shadows over Innistrad
“Investigate” means “Put a colorless Clue artifact token onto the battlefield. It has ‘{2}, Sacrifice this artifact: Draw a card.’”