Historical Rules · 14 November 2025
Rule 509.4
Official source text from the 14 November 2025 Rules release
If a creature is put onto the battlefield blocking, its controller chooses which attacking creature it’s blocking as it enters the battlefield (unless the effect that put it onto the battlefield specifies what it’s blocking). A creature put onto the battlefield this way is “blocking” but, for the purposes of trigger events and effects, it never “blocked.”