Define: in rem

"in rem" relates to jurisdiction and means thing

A court which grants a divorce exercises in rem jurisdiction over the marriage.

Jurisdiction in rem

assumes the property or status is the primary object of the action, rather than personal liabilities not necessarily associated with the property

Define: Agency, standing, capacity

Agency law is concerned with any "principal"-"agent" relationship; a relationship in which one person has legal authority to act for another. Such relationships arise from explicit appointment, or by implication. The relationships generally associated with agency law include guardian-ward, executor or administrator-decedent, and employer-employee.

Standing, or locus standi, is capacity of a party to bring suit in court. State laws define standing. At the heart of these statutes is the requirement that plaintiffs have sustained or will sustain direct injury or harm and that this harm is redressable.
At the Federal level, legal actions cannot be brought simply on the ground that an individual or group is displeased with a government action or law. Federal courts only have constitutional authority to resolve actual disputes. Only those with enough direct stake in an action or law have "standing" to challenge it.
In contract law, a person's ability to satisfy the elements required for someone to enter binding contracts.  For example, capacity rules often require a person to have reached a minimum age and to have soundness of mind.