A more thorough explanation:

A bill of particulars is a legal document that lists the specific details of the claims made by the plaintiff in a lawsuit. It is a written itemization that the defendant may demand in some situations to clarify the details of the claims.

For example, in the case of United States v. Davis, the defendant demanded a bill of particulars to specify the exact dates and locations of the alleged criminal activity. In Boumediene v. Bush, the detainees at Guantanamo Bay requested a bill of particulars to clarify the specific charges against them.

These examples illustrate how a bill of particulars can be used to provide more specific information about the claims made in a lawsuit. It can help the defendant understand the allegations against them and prepare a defense.