in re

"LAW.COM Dictionary":
prep. short for "in regard to" or concerning. Often "in re" is found near the top of lawyers' letters to identify the subject matter, as "In re Matheson v. Roth," or "In re Estate of Ruth Bentley." It is also used in naming legal actions in which there is only one party, the petitioning party, as in "In re Adoption of Marcus McGillicuddy."