What action must a defendant take to formally indicate their participation in civil proceedings?

The correct action for a defendant to formally indicate their participation in civil proceedings is to file a notice of appearance. This document serves as the defendant's official entry into the court proceedings, signaling to the court and the plaintiff that the defendant intends to respond to the claims made against them.

Filing a notice of appearance is essential because it establishes that the defendant is engaged in the litigation process, allowing them to assert their rights and defenses. It is a critical procedural step that lays the groundwork for subsequent pleadings, such as a notice of defense, which might follow but is not the initial step of participation in the case.

This procedural requirement is structured to ensure clarity in the proceedings, as it allows the court to understand who is involved and ensure that all parties are adequately notified about the proceedings. By formally entering the case through a notice of appearance, the defendant protects their legal interests and confirms their intent to litigate rather than allowing a default judgment due to non-response.