Revealing Wind — ruling 1

You can cast Revealing Wind even if there are no face-down creatures attacking or blocking. The damage-prevention effect will still apply.

Revealing Wind : règles, fonctionnement et interactions (MTG)

Revealing Wind is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Prevent all combat damage that would be dealt this turn. You may look at each face-down creature that's attacking or blocking.

How it works : Revealing Wind

Original English text — Wizards of the Coast / Scryfall

#1February 25, 2015· Wizards of the Coast
You can cast Revealing Wind even if there are no face-down creatures attacking or blocking. The damage-prevention effect will still apply.
No other card is named in this ruling.