Titular (Catholic Church)

In Roman Catholicism, a titular is a cardinal who holds a titulus, one of the main churches of Rome. Such holders were initially by tradition native-born Romans (of high social standing). The first church in Rome to have a non-Italian titular was Santi Quattro Coronati: Dietrich of Trier was appointed titular in 975 by Pope Benedict VII. That basilica was originally Titulus Aemilianae, drawing its name in characteristic fashion from its foundress, who doubtless owned the extensive suburban Roman villa whose foundations remain under the church and whose audience hall became the ecclesiastical basilica. The term also applies to the holder of a titular see, which is a nominal (often former) episcopal or archiepiscopal see without an actual pastoral flock which confers the rank of titular (arch)bishop on its incumbent.

What is this?