The manuscript is a large composite work whose codices and fragments were collected and united in a single volume by Edward Lhuyd. In their catalogue description, Abbott and Gwynn give its constituent sections as given below. The tables of contents provided in the entries linked below are also based on their description. In addition to paraphrasing or citing the catalogue, however, the tables build on it in order to provide a new, updated version within the overall framework of the catalogue. Most of the additional information is drawn from sources on the individual texts that are contained in the manuscript. Please note that there are still omissions that need to be addressed and that more work is needed to provide an overview of the scholia and glosses.(1)n. 1 T. K. Abbott • E. J. Gwynn, Catalogue of Irish MSS in TCD (1921): 94–131 and its supplement.
1 f. Fragment 1 of Betha Féchín Fabair. First folio of a section which continues in col. 125 below. The pages of this folio, numbered 1 and 2, contain two columns each.
20 ff. Sanas Cormaic (cols. 3-87, written by Iolland and Torna Ó Maoil Chonaire) and O'Mulconry's glossary (A-T).
pp. 123-124 (1 f.). Fragment of TBDD.
1 f. Fragment 2 of Betha Féchín Fabair. Second folio of the section beginning at p. 1 (col. 1a) above.
23 ff. A duanaire of Classical Irish verse.
16 ff. Miscellany of religious and secular literature. Written in 1407 by Donnchad Ó Duinín for Fingín Ó Mathghamhna.
16 ff. Miscellany of religious and secular literature. Scribe: Murchadh Ó Cuindlis.
6 ff. Fragment of an Early Modern Irish version of Táin bó Flidaise.
Letter by Tadhg Ó Rodaighe (c. 1700).
8 ff. The Yellow Book of Lecan proper. The title occurs in a marginal note in col. 380 by Ciothruad mac Taidg Ruaid.
9 ff. Dinnshenchas Érenn (fragment).
10 ff. Medical. Irish translation of Rosa Anglica.
3 ff. Medical tract.
4 ff. Medical. On the Aphorisms of Hippocrates.
18 1/2 ff. Learned and gnomic literature (Auraicept na n-éces, etc.).
99 ff. Miscellany mostly written by Giolla Íosa Mac Fhirbhisigh in about 1391. It currently falls into twelve sections. It includes early Irish narrative works such as Táin bó Cúailnge (cols 573-619) and Togail bruidne Da Derga (cols 716-739b).
4 ff. A manuscript no longer in YBL, but now existing separately as NLI G 4.
