SMS Poll Keyword is used to identify the poll, it's used in conjunction with option, people will text the poll keyword and option to vote for polling participants.
For example if you're doing dance competition and want people to cast their votes for participants. You can choose a keyword to identify your sms poll, such as "DANCE" and each contestant in the competition in an option for people to choose or cast vote for.
You may designated option 1,2,3,4... for each participants or their nick names.
If someone wants to vote for contestant 3, they would text "DANCE3" to shortcode.
Please note that there shall not be any special characters like _, #, $ etc in your keywords.