It indicates the main fields. Be aware that, depending on the year of catalogueing, there is some variation in assignments. Although at present articles are assinged up to 3 main fields, articles catalogued before 2012 have one primary field in principle. The following is the list of fields:
Characteristics of Japanese language, Overview of Japanese language, History of research on Japanese language, etc.
Genealogy of Japanese language, Diachronic research on Japanese language, Overview of modern Japanese, etc.
Phonology, phonetics, accent, etc. Studies on the phonology of the various regional dialect of Japan are categorized under “Dialects.”
Chinese characters, Kanadukai, Usage of characters, Theory of orthography, etc.
Lexicography, Word structure, Synonyms, Loan words, etc.
Grammatical theory, Syntax, Modality, etc.
Genre studies, Rhetoric, Stylometry, etc.
General theory of dialects, description of regional dialects, etc.
Corpora, Databases, Machine translation, etc. Topics in communication through the internet, digital media, etc. are categorized under “Communication.”
Language contact, Language behavior, Sociolinguistics, etc.
The language of television and newspapers, etc.
Language policy, Script reform, Chinese characters designated for common use, etc.
Education in Language Arts classes, Child language acquisition, etc.
Pedagogy of Japanese language education, Materials, Praxis, Issues involving students and teachers, etc.
General theories of language including Japanese, Psycholinguistics, Contrastive linguistics, etc.
Encyclopedias, Dictionaries. Only “Book” is included in this field.
Indexes, Resources for Japanese language research, etc.
Review articles on Japanese language research, etc.