Complex sentence: Manuscripts are now designated by library, bookpress, and number: for example, the manuscript of "Beowulf" is designated "Cotton Vitellius A.xv", and the manuscript of "Pearl" is "Cotton Nero A.x".
Split into simpler sentences: Manuscripts are now designated by library, bookpress, and number. For example, the manuscript of "Beowulf" is designated "Cotton Vitellius A.xv", and the manuscript of "Pearl" is "Cotton Nero A.x".