Can you target a hidden (facedown) card with a spell that targets a unit or gear on the battlefield?

Ruling: You can target a hidden card if the spell allows targeting "facedown cards," but you cannot target a hidden card with a spell that specifically targets "unit" or "gear" because a facedown card is not a unit or gear for targeting purposes.

Nuances:

• A facedown card exists in a public zone and is publicly visible as a facedown card
• "Unit" and "gear" refer to objects on the Board unless specified otherwise
• "Facedown card" refers to a card in a Facedown Zone unless specified otherwise
• The FAQ is retired and patch notes are not rules text