In this rule

Historical Rules · 20 November 2020

Rule 711.10a

Official source text from the 20 November 2020 Rules release

Permalink

If a spell or ability puts a transforming double-faced card onto the battlefield “transformed,” it enters the battlefield with its back face up. If a player is instructed to put a card that isn’t a transforming double-faced card onto the battlefield transformed, that card stays in its current zone.

Find this number in the current Rules