How have emoji been encoded on cell phones?
Cell phone carriers in Japan have long encoded some emoji in Shift-JIS and ISO-2022 as extensions of the JIS X 0208 character set. A core set of 722 emoji constitutes the union of the emoji sets encoded in this way by the three most popular cell phone carriers in Japan. These core emoji characters are interchanged as plain text by millions of people daily (in SMS text messages and e-mail subject lines, for example) , and need to be handled by e-mail systems, search engines, publishing systems, databases, and so on. For emoji beyond this core set (including those that are still being created), vendors have added rich text support, and use approaches such as embedded graphics. Similar techniques (embedded graphics or escape tags designating emoji) are also typically used for emoji support in China and the Republic of Korea.
