From PHPBB用户手册

# Table: 'phpbb_forums'
CREATE TABLE phpbb_forums (
	forum_id mediumint(8) UNSIGNED NOT NULL auto_increment, 版面ID
	parent_id mediumint(8) UNSIGNED DEFAULT '0' NOT NULL, 版面隶属的上一级版面ID, 如果自己为根版面, 则此值为0
	left_id mediumint(8) UNSIGNED DEFAULT '0' NOT NULL, 此版面所包含的子版面ID的left_id必须大于这个值
	right_id mediumint(8) UNSIGNED DEFAULT '0' NOT NULL, 此版面所包含的子版面的right_id必须小于这个值
	forum_parents mediumtext NOT NULL, 内容为一个多级数组, 包含父版面的信息
	forum_name varchar(255) DEFAULT '' NOT NULL, 版面名称
	forum_desc text NOT NULL, 版面描述
	forum_desc_bitfield varchar(255) DEFAULT '' NOT NULL, ??
	forum_desc_options int(11) UNSIGNED DEFAULT '7' NOT NULL, ??
	forum_desc_uid varchar(5) DEFAULT '' NOT NULL, 版面描述区分码
	forum_link varchar(255) DEFAULT '' NOT NULL, 版面链接
	forum_password varchar(40) DEFAULT '' NOT NULL, 版面密码
	forum_style smallint(4) UNSIGNED DEFAULT '0' NOT NULL, 版面风格
	forum_image varchar(255) DEFAULT '' NOT NULL, 版面图标
	forum_rules text NOT NULL, 版面规则
	forum_rules_link varchar(255) DEFAULT '' NOT NULL, 版面规则链接
	forum_rules_bitfield varchar(255) DEFAULT '' NOT NULL, ??
	forum_rules_options int(11) UNSIGNED DEFAULT '7' NOT NULL,
	forum_rules_uid varchar(5) DEFAULT '' NOT NULL, 版面规则区分码
	forum_topics_per_page tinyint(4) DEFAULT '0' NOT NULL, 版面每页显示的话题数
	forum_type tinyint(4) DEFAULT '0' NOT NULL, 版面类型
	forum_status tinyint(4) DEFAULT '0' NOT NULL, 版面状态
	forum_posts mediumint(8) UNSIGNED DEFAULT '0' NOT NULL, 版面文章数
	forum_topics mediumint(8) UNSIGNED DEFAULT '0' NOT NULL, 版面话题数
	forum_topics_real mediumint(8) UNSIGNED DEFAULT '0' NOT NULL, 版面真实话题数 ??
	forum_last_post_id mediumint(8) UNSIGNED DEFAULT '0' NOT NULL, 版面最后文章的ID
	forum_last_poster_id mediumint(8) UNSIGNED DEFAULT '0' NOT NULL, 版面最后发表者的用户ID
	forum_last_post_subject varchar(100) DEFAULT '' NOT NULL, 版面最后文章的标题
	forum_last_post_time int(11) UNSIGNED DEFAULT '0' NOT NULL, 版面最后文章的发表时间
	forum_last_poster_name varchar(255) DEFAULT '' NOT NULL, 版面最后文章发表者的名称
	forum_last_poster_colour varchar(6) DEFAULT '' NOT NULL, 版面最后文章发表者的颜色
	forum_flags tinyint(4) DEFAULT '32' NOT NULL, ??
	display_on_index tinyint(1) UNSIGNED DEFAULT '1' NOT NULL, 是否显示在首页
	enable_indexing tinyint(1) UNSIGNED DEFAULT '1' NOT NULL, 是否加入检索
	enable_icons tinyint(1) UNSIGNED DEFAULT '1' NOT NULL, 是否允许主题图标
	enable_prune tinyint(1) UNSIGNED DEFAULT '0' NOT NULL, 是否开启自动删文
	prune_next int(11) UNSIGNED DEFAULT '0' NOT NULL, 
	prune_days mediumint(8) UNSIGNED DEFAULT '0' NOT NULL, 删除多少天未回复的文章
	prune_viewed mediumint(8) UNSIGNED DEFAULT '0' NOT NULL, ??
	prune_freq mediumint(8) UNSIGNED DEFAULT '0' NOT NULL, ??
	PRIMARY KEY (forum_id),
	KEY left_right_id (left_id, right_id),
	KEY forum_lastpost_id (forum_last_post_id)
) CHARACTER SET `utf8` COLLATE `utf8_bin`;