It ranks as one of the three major surviving Irish manuscripts to have been produced in pre-Norman Ireland, the two other works being the Lebor na hUidre and the Book of Leinster.
Some scholars have also called it the Book of Glendalough, in Irish Lebar Glinne Dá Locha, after several allusions in medieval and early modern sources to a manuscript of that name.
[2] Pádraig Ó Riain states ".. a rich, as yet largely unworked, source of information on the concerns of the community at Glendalough in or about the year 1131, and a magnificent witness, as yet barely interrogated, to the high standard of scholarship attained by this monastic centre.
The manuscript contains many Leinster narratives belonging to the Cycles of the Kings, some of which are grouped in a section which is headed Scélshenchas Laigen, beginning with Orgain Denna Ríg.
Other verse texts include the wisdom poems Immacallam in Dá Thuarad ("The Colloquy of the Two Sages") and the legal instructional dialogue Gúbretha Caratniad ("False judgments of Caratnia").
Sir James Ware himself referred to the second part as the Saltair na Rann by Óengus Céile Dé, after the metrical religious work of this name beginning on the first folio (fo.
Caoimhín Breatnach assumes that they did, but Pádraig Ó Riain has expressed serious reservations, suggesting instead that the title may have been a convenient shorthand introduced by Ware in the 1630s and adopted by some of his contemporaries.
[3] A case has been made for identifying Rawlinson B 502 (second part) as the manuscript referred to in some sources as the Lebar Glinne Dá Locha or Book of Glendalough.
References to this title in the manuscripts include: The case for identification was made by scholars like Eugene O'Curry (1861) and James Carney (1964), but it has been argued most forcefully and elaborately by Pádraig Ó Riain.
Caoimhín Breatnach, however, criticises his methodology in establishing textual relationships and concludes that Lebar Glinne Dá Locha and Rawlinson B 502 are two separate manuscripts.
[21] Breatnach suggests that these shared differences are unlikely to have occurred independent of one another, but probably derive from a common source known to both scribes as the Lebar Glinne Dá Locha.
[21] Breatnach also points out that Geoffrey Keating, in a list of extant manuscripts known to him, distinguishes between the Saltair na Rann by Óengus Céile Dé, i.e. Rawlinson B 502 (second part), and the Book of Glendalough.