TEXT[(M)] [CHARACTER SET charset_name] [COLLATE collation_name]

A TEXT column with a maximum length of 65,535 (216 - 1) characters.

An optional length M can be given for this type. If this is done, MySQL
creates the column as the smallest TEXT type large enough to hold
values M characters long.

URL: http://dev.mysql.com/doc/refman/5.0/en/string-type-overview.html

