39 CFR 966.7: Answer to petition.

Within thirty (30) days after the date of receipt of the petition, the General Counsel shall file an answer to the petition, and attach all available relevant records and documents in support of the Postal Service's claim, or the administrative offset schedule proposed by the Postal Service for collecting any such claim. The answer shall provide a clear and detailed description of the basis for the Postal Service's determination of the alleged debt and its calculation of the amount of the alleged debt and/or its proposed offset schedule, as appropriate.