Each case in progress is identified by a number of elements:
For example, the citation of an appellate brief of a pending criminal case in the Supreme Judicial Court of Massachusetts would be:
Brief of Appellee, Commonwealth v. Joseph Cousin, No. SJC-12252 (Mass. July 2017).
A citation for an appellate brief for a federal Supreme Court case would look like this:
Brief of Respondent, Trump v. International Refugee Assistance Project, No. 16-1436 (U.S. June 12, 2017).