A more thorough explanation:

An anonymous case is a legal case where the name of at least one party is replaced with the word "anonymous" to keep their identity a secret. For example, in the case of Anonymous v. Anonymous, the court used the word "anonymous" instead of a person's name.

This is done to protect the privacy of the parties involved, especially in cases where sensitive or personal information is being discussed. It is also used in cases where the identity of a party could put them in danger or harm their reputation.

For instance, in a child custody case, the court may use "anonymous" instead of the child's name to protect their privacy. Similarly, in a case involving a victim of sexual assault, the court may use "anonymous" instead of the victim's name to prevent further harm or trauma.