MySQL and comments

http://dev.mysql.com/doc/refman/5.0/en/create-table.html

table_option:
    {ENGINE|TYPE} [=] engine_name
  | AUTO_INCREMENT [=] value
  | AVG_ROW_LENGTH [=] value
  | [DEFAULT] CHARACTER SET [=] charset_name
  | CHECKSUM [=] {0 | 1}
  | [DEFAULT] COLLATE [=] collation_name
  | COMMENT [=] 'string'

Example:

CREATE TABLE foo (
  id int(10) NOT NULL auto_increment COMMENT 'unique ID for each foo entry',
  bar varchar(255) default NULL COMMENT 'the bar of the foo',
  ....
) TYPE=MyISAM;