A manuscript which includes theological passages (pp. 1-9); a treatise on Cerdd Dafod (pp. 10-16); Cyfrinach y Beirdd (pp. 33-68); Bonedd y Saint (pp. 69-79); pedigrees (pp. 80-84); Cynghorau Catwn Ddoeth (pp. 98-99); medical recipes (112); astronomy (pp. 123-124); Daniel's interpretation of dreams (pp. 126-133); the Book of Fate (pp. 186-212); the Lives of Saints Margaret (p. 145-167, 177-178, 183-184) and Catherine (pp. 167-176, 179-182); etc. The manuscript was written by Gutun Owain (fl. 1450-1498) (see p. 33) in two styles: pp. 33-101, l. 9 and p. 125, ll. 1-6 are in a formal book hand, and the remainder of the text is in cursive writing; however, a combination of both hands occurs on p. 142. The text on p. 94 is imperfect.
For pp. 98-99 (Kynghorav kadw ddoeth ...) cf. Peniarth MS 27, p. 16; for pp. 101-111, 134-135 (Si deus est animus nobilis ...) cf. ibid., p. 17. For the missing folio before p. 213 see Peniarth MS 86, p. 187. For p. 222 (Llyma vrrevddwyd Grono ddv ...) see Mostyn MS 110, p. 215, which has a transcript of this manuscript.