The Doctor's symbol

The Doctor's symbol was a sigil created by the Thirteenth Doctor to embody the ethos of being "the Doctor". (PROSE: Meet the Fam)

Appearance
The Doctor's symbol was a broadly circular design. The English words "BE MORE DOCTOR", in white sans-serif capital letters, appeared over a black-and-white depiction of the Doctor's TARDIS's police box-like exterior. The background was a gradient, going from yellow to red from left to right. Circular Gallifreyan symbols were overlaid on top of the rest of the design. (PROSE: Meet the Fam)

History
The Thirteenth Doctor conceived the symbol some time during or prior to her becoming stranded in the dog dimension. While there, she used the symbol in a book she managed to send back to N-Space to mark out pieces of advice directly from her. (PROSE: Meet the Fam)