二重イタリック体資本D ⅅ

What are unfilled letters with inner and outer thin outlines usually called? Double struck. Some of these symbols are used to represent sets of natural, integer, rational, complex, and other numbers, such as ℕ , ℤ , ℚ .

Other double-stroke symbols, such as the double-struck italic uppercase letter 「D」, do not have a strictly defined purpose. You can use them for writing formulas and calculations, as well as for decorating text.

シンボル「二重イタリック体資本D」は「文字様記号」ブロックの「二重線の斜体数学記号」サブブロックに含まれており、2002年にUnicodeバージョン3.2の一部として承認されました。