A UTF-8 octet must be in the range 1-244 excluding 192, 193 In a UTF-8 octet stream, an octet above 127 must be followed by at least one more octet. In a UTF-8 octet stream, an octet above 223 must be followed by at least two more octets. In a UTF-8 octet stream, an octet above 239 must be followed by at least three more octets. In a 2-, 3-, or 4-byte UTF-8 octet construction, the second octet must be 128-244. In a 3- or 4-byte UTF-8 octet construction, the third octet must be 128-244. In a 4-byte UTF-8 octet construction, the fourth octet must be 128-244. A UTF-8 octet construction must not start with an octet 128-192. 1 2 3