Alphabet

An alphabet was a system of letters. There were twenty-six letters in the English language alphabet, the first sixteen of which were A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, and P; the last nine letters of the alphabet were R, S, T, V, U, W, X, Y and Z. (TV: The Masque of Mandragora, Midnight, Goodbye, Sarah Jane Smith, AUDIO: A Death in the Family)

While under mental attack by the Mandragora Helix, the Fourth Doctor and Sarah Jane Smith spoke the alphabet backwards to concentrate. (TV: The Masque of Mandragora)

In 2028, under the influence of Nobody No-One, a cardiogram once sung the alphabet from A to P. (AUDIO: A Death in the Family)

The Tenth Doctor and the entity possessing Sky Silvestry spoke the first fifteen letters of the alphabet simultaneously. (TV: Midnight)

River Song, while unaware of the Twelfth Doctor's identity, threatened to remove their organs in alphabetical order, to which the Doctor facetiously asked "Which alphabet?" (TV: The Husbands of River Song)