Metalanguage is an essential linguistic mechanism which allows us to communicate explicit information about language itself. However, it has been underexamined in research in language technologies, to the detriment of the performance of systems that could exploit it. This paper describes the creation of the first tagged and delineated corpus of English metalanguage, accompanied by an explicit definition and a rubric for identifying the phenomenon in text. This resource will provide a basis for further studies of metalanguage and enable its utilization in language technologies.