Block: Enclosed Alphanumeric Supplement

Range U+1F100 - U+1F1FF
Official Chart http://www.unicode.org/charts/PDF/U1F100.pdf
Wikipedia Enclosed Alphanumeric Supplement is a Unicode block consisting Latin alphabet characters and Arabic numerals enclosed in circles, ovals or boxes, used for a variety of purposes. It is encoded in the range U+1F100U+1F1FF in the Supplementary Multilingual Plane.
The block is mostly an extension of the Enclosed Alphanumerics block, containing further enclosed alphanumeric characters which are not included in that block or Enclosed CJK Letters and Months.
https://en.wikipedia.org/wiki/Enclosed_Alphanumeric_Supplement
Characters
🄀 🄁 🄂 🄃 🄄 🄅 🄆 🄇 🄈 🄉 🄊 🄋 🄌 🄍 🄎 🄏 🄐 🄑 🄒 🄓 🄔 🄕 🄖 🄗 🄘 🄙 🄚 🄛 🄜 🄝 🄞 🄟 🄠 🄡 🄢 🄣 🄤 🄥 🄦 🄧 🄨 🄩 🄪 🄫 🄬 🄭 🄮 🄯 🄰 🄱 🄲 🄳 🄴 🄵 🄶 🄷 🄸 🄹 🄺 🄻 🄼 🄽 🄾 🄿 🅀 🅁 🅂 🅃 🅄 🅅 🅆 🅇 🅈 🅉 🅊 🅋 🅌 🅍 🅎 🅏 🅐 🅑 🅒 🅓 🅔 🅕 🅖 🅗 🅘 🅙 🅚 🅛 🅜 🅝 🅞 🅟 🅠 🅡 🅢 🅣 🅤 🅥 🅦 🅧 🅨 🅩 🅪 🅫 🅬 🅭 🅮 🅯 🅰 🅱 🅲 🅳 🅴 🅵 🅶 🅷 🅸 🅹 🅺 🅻 🅼 🅽 🅾 🅿 🆀 🆁 🆂 🆃 🆄 🆅 🆆 🆇 🆈 🆉 🆊 🆋 🆌 🆍 🆎 🆏 🆐 🆑 🆒 🆓 🆔 🆕 🆖 🆗 🆘 🆙 🆚 🆛 🆜 🆝 🆞 🆟 🆠 🆡 🆢 🆣 🆤 🆥 🆦 🆧 🆨 🆩 🆪 🆫 🆬 🆭 🆮 🆯 🆰 🆱 🆲 🆳 🆴 🆵 🆶 🆷 🆸 🆹 🆺 🆻 🆼 🆽 🆾 🆿 🇀 🇁 🇂 🇃 🇄 🇅 🇆 🇇 🇈 🇉 🇊 🇋 🇌 🇍 🇎 🇏 🇐 🇑 🇒 🇓 🇔 🇕 🇖 🇗 🇘 🇙 🇚 🇛 🇜 🇝 🇞 🇟 🇠 🇡 🇢 🇣 🇤 🇥 🇦 🇧 🇨 🇩 🇪 🇫 🇬 🇭 🇮 🇯 🇰 🇱 🇲 🇳 🇴 🇵 🇶 🇷 🇸 🇹 🇺 🇻 🇼 🇽 🇾 🇿