Del. Code tit. 15, § 2002

Each person appointed under § 2001 of this title shall appear before the Department to qualify by taking and subscribing to the prescribed oath (or affirmation) and to receive suitable instruction after due notice from the Department, which shall be given at least 7 days before the times appointed for the appearance of the registration officers. No person shall be excused from the obligation unless that person shall have become disqualified by sickness, disability or otherwise.