CCCC MS 449 is a manuscript of the Glossary and Grammar by Ælfric of Eynsham OSB (d. 1010). The original eleventh-century portion was obviously badly incomplete by the time Parker acquired it, and he had the missing parts of the text supplied by one of his own scribes. Ælfric's Grammar was one of the first instructional texts on Latin to be written in a vernacular; as such it was extremely useful for early modern scholars who could use the Latin material to learn Old English.