TAKTIKÄ. - The expression derived from the word *taxis* (= order) was applied to lists of civil and ecclesiastical dignities (*Notitiae dignitatum*), among which the famous list written at the end of the 4th century is notable: *Notitia dignitatum omnium tam civilium quam militarium*, with its two parts (*Oriens-Occidens*) in the edition by Seck (Berlin 1876). Today, however, the term is rather used for lists of Byzantine ecclesiastical geography, of which several exist from different centuries.
Very famous are the *T.* of Leo VI (end of the 9th century), the *Nea T.* of Constantine Porphyrogenitus (10th century), the *Ecclesia* of Andronicus Palaeologus (14th century); but other lists also exist, such as those of Epiphanius (4th century), George of Cyprus (7th century), and Nilus Doxopatrius (12th century). The schema of the Byzantine lists generally has four parts: 1) patriarchs; 2) metropolitans; 3) archbishops (autocephalous); 4) bishops; these parts do not contain the names of the prelates, but only their sees. Of great importance for completing and authenticating these lists are the subscriptions of the synodal fathers in ecumenical councils. Liturgical sources (diptychs, synodika), diplomatic sources (imperial and ecclesiastical), literary sources, and epigraphic sources should not be overlooked in establishing accurate lists. The Assumptionist Fathers have begun the publication of a *Corpus notitiarum episcopatuum* to carry out a project of the late Gerland.