This phrase is often used to describe a person who acts as a locum tenens ('placeholder') in the absence of a superior, such as the president pro tempore of the U.S. Senate, who acts in place of the president of the United States Senate—a position that is held ex officio by the current vice president of the United States.
These positions ostensibly go to legislators experienced in floor debate, who are familiar with the content and application of relevant rules and precedents and who have a reputation for fairness among their colleagues.
[3] A common use of pro tempore in the United States is in municipalities such as cities and towns with regard to the position of the mayor.
They typically have to meet some basic criteria to qualify, and often serve as neutrals or mediators in alternative dispute resolution processes.
[10] Universities sometimes appoint heads of faculties temporarily until ratified by a board of governors or senate committee.