In re, Latin

Latin

Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 for "in the matter [of]", is a term with several different, but related meanings.

In correspondence, the phrase in re: refers to the subject of a letter

Letter

A letter is a written message from one party to another. The role of letters in communication has changed significantly since the nineteenth century...

, memorandum

Memorandum

A memorandum is from the Latin verbal phrase memorandum est, the gerundive form of the verb memoro, "to mention, call to mind, recount, relate", which means "It must be remembered ..."...

, or electronic mail message. It is used especially in e-mail to denote in regards to; confusingly, RE: is employed to mean in reply to:.

In jurisprudence

Jurisprudence

Jurisprudence is the theory and philosophy of law. Scholars of jurisprudence, or legal theorists , hope to obtain a deeper understanding of the nature of law, of legal reasoning, legal systems and of legal institutions...

, in re: is used to indicate that a judicial proceeding may not have formally designated adverse parties or is otherwise uncontested. The term is commonly used in case citations of probate

Probate

Probate is the legal process of administering the estate of a deceased person by resolving all claims and distributing the deceased person's property under the valid will. A probate court decides the validity of a testator's will...

 proceedings, for example, In re Marriage Cases

In re Marriage Cases

In re Marriage Cases 43 Cal.4th 757 [76 Cal.Rptr.3d 683, 183 P.3d 384], was a California Supreme Court case with the dual holding that "statutes that treat persons differently because of their sexual orientation should be subjected to strict scrutiny" and the existing "California legislative and...

; it is also used in juvenile court

Juvenile court

A juvenile court is a tribunal having special authority to try and pass judgments for crimes committed by children or adolescents who have not attained the age of majority...

s, as, for instance, In re Gault

In Re Gault

In re Gault, 387 U.S. 1 , was a landmark U.S. Supreme Court decision that held that juveniles accused of crimes in a delinquency proceeding must be afforded many of the same due process rights as adults, such as the right to timely notification of the charges, the right to confront witnesses, the...

.