二重イタリック体小D ⅆ

Lowercase 「d」 is often used to denote diameter, distance, differential, and one of the varieties of quarks, as well as other mathematical and scientific phenomena. As for formulas and calculations, the italic 𝑑 , bold small 𝐝 , handwritten 𝒹 from the 数学用英数字記号  1D400–1D7FF are used.

Double-struck lowercase 「d」 is rarely seen in scientific works. This unfilled letter with a double outline is commonly used for decorative purposes in texts. Copy and paste it in your nickname or title, on a business card or promotional brochure. This letter combines well with other double-lined symbols from Unicode, such as ⅇ , ⅈ , ⅉ .

シンボル「二重イタリック体小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。