A player can be placed on the Disqualified List if he violates the terms of his contract (usually involving a refusal to render service and/or an unexcused absence).
A player can be placed on the Disqualified List only with the approval of the MLB Commissioner.
A player on the Disqualified List does not count against the club's Active List or Reserve List, and he does not accrue service time or get paid while on the list.
An MLB player on the Disqualified List cannot be reinstated from August 1st through October 31st, and a minor league player on the Disqualified List cannot be reinstated from August 1st through the end of his club's season (including post-season).
A player reinstated from the Disqualified List must be added back to his club's Reserve List within 30 days if the reinstatement is made during the club's championship season (regular season) prior to August 1st, or by Opening Day of the following season if the player is reinstated from the Disqualified List during the off season, but if the player is assigned to another club after reinstatement he must be placed on that club's Reserve List immediately.