Crossed Computers

Crossed Computers was the symbol of the maternity service on Gallifrey. When Organon asked the Fourth Doctor what sign he was born under, the Doctor joked that he was born under the sign of the Crossed Computers. (TV: The Creature from the Pit).

However, since the Thirteenth Doctor learned from the secret of her own past lives as the Timeless Child, the true circumstances of the Doctor's Gallifreyan "birth" are unclear, as large portions of the Matrix pertaining to the Timeless Child's life were redacted beyond even the Master's ability to recover it. (TV: The Timeless Children)