If a character set is specified, then append MySQL specific SQL to the column definition.
If a character set is specified, then append MySQL specific SQL to the column definition.
If Unicode is specified without a collation, then use the utf8_unicode_ci collation. While utf8_general_ci is MySQL's default utf8 collation (at least for 5.5), and is faster, it is also incorrect; see http://stackoverflow.com/questions/766809/ .
the SQL for the data type
an optional character set
Map Unicode to the "utf8" UTF-8 character set. If Unicode is specified without a collation then use the "utf8_unicode_ci" collation. If a non-Unicode character set is specified then let MySQL pick its default collation for the character set. See http://dev.mysql.com/doc/refman/5.5/en/charset-charsets.html for more information.