Specifically, two major GEC corpora have different taxonomies: the Cambridge Learner Corpus (CLC) (Nicholls, 2003) has 80 tags, which generally represent the word class of the error and the type of error (such as replace preposition, unnecessary pronoun, or missing determiner).
the NUS Corpus of Learner English (NUCLE) (Dahlmeier et al., 2013) has only 27 error types.