A party may direct written interrogatories to any other party. A copy of the interrogatories shall be served on all other parties entitled to notice.The producing party shall furnish an affidavit stating whether the production is complete in accordance with the request. Service of discovery shall be made in the manner provided for service of documents in Rule 11. (n) Claims of Privilege. Interrogatories are written questions that one party sends to the other. The receiving party is required to answer these questions under oath. A form of the notice is appended to the rule. A sample request for production of documents (RFP) (also called a document request) that counsel may use in Illinois circuit court civil litigation. These interrogatories and document production requests are of a continuing nature.