From PHPBB用户手册

# Table: 'phpbb_disallow'
CREATE TABLE phpbb_disallow (
	disallow_id mediumint(8) UNSIGNED NOT NULL auto_increment, ID
	disallow_username varchar(255) DEFAULT '' NOT NULL, 禁止使用的用户名
	PRIMARY KEY (disallow_id)
) CHARACTER SET `utf8` COLLATE `utf8_bin`;