Crossed Computers

Crossed Computers was the sign under which the Doctor was born, and also the symbol of the maternity service on Gallifrey. It was considered a favourable celestial conjunction.

The Fourth Doctor mentioned as such to Lady Adrasta's astrologer Organon. (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)

Behind the scenes

 * To date, the Doctor remains the only Time Lord character in the series to have their birth sign revealed on-screen; and the Crossed Computers sign was never mentioned again in the Classic Series.