Given the task definition and input, reply with output. In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.

Saint-Denis is the administrative capital ( " pre ́ fecture " ) of the French controlled island of Re ́ union , in the Indian Ocean .

Saint-Denis ( -RSB- , or unofficially Saint-Denis de la Re ́ union for disambiguation ) is the " pre ́ fecture " ( administrative capital ) of the French overseas region and department of Re ́ union , in the Indian Ocean .