--- /dev/null
+-- Stores the groups the user has once belonged to.
+-- The user may still belong these groups. Check user_groups.
+CREATE TABLE /*_*/user_former_groups (
+ -- Key to user_id
+ ufg_user int unsigned NOT NULL default 0,
+ ufg_group varbinary(255) NOT NULL default ''
+) /*$wgDBTableOptions*/;
+
+CREATE UNIQUE INDEX /*i*/ufg_user_group ON /*_*/user_former_groups (ufg_user,ufg_group);