(a) Generally. When authorized by the ALJ, a party may conduct discovery by serving written interrogatories on any other party. Unless the parties agree or the ALJ orders otherwise, a party may not serve more than 20 written interrogatories on each party. For purposes of the 20-interrogatory limitation, each discrete subpart of an interrogatory counts as a separate interrogatory.

(b) Answers and objections. Unless a longer or shorter time period is agreed to by the parties or ordered by the ALJ, answers and objections must be served within 28 days of service of the interrogatories. Each interrogatory must be answered separately and fully in writing, unless it is objected to, in whole or in part, in which event the reasons for the objection must be stated with specificity in place of the answer. Answers and objections must be signed in accordance with § 4.112(e). Answers must be signed by the person providing the answer, and objections must be signed by the party's representative or the party, if unrepresented.