Deduction for authors' professional income: allowed on copyright consideration for eligible Indian-language textbooks, subject to prescribed conditions. Deduction permits a specified portion of income of a resident individual author from lump sum consideration for assignment or grant of copyright, or royalties or copyright fees (including non-returnable advances) in respect of a qualifying book, to be allowed in computing total income; eligibility requires the book to be a dictionary, thesaurus, encyclopaedia or prescribed university text and to be in an Eighth Schedule language or a language notified by the Central Government.