What is Unicode?
When you activate Unicode in your campaign, it allows you to use characters outside of the standard GSM character set that is most commonly used in mobile communications. Unicode can therefore use the standard GSM character set and character sets that are common in Arabic, Chinese and other languages altogether.
When typing a message, a warning
Activate UNICODE to display the message correctly shows up if your characters are outside of the standard GSM character set. This message could be illegible to a recipient if you would not activate Unicode.
When you activate Unicode in your campaign, length of message is limited to 70 characters as opposed to 160 in the standard SMS.