In Eastern Orthodoxy, a diataxis (διάταξις, 'order'; plural diataxeis) is a guidebook for the service of the Divine Liturgy.
[2] Diataxeis consist of rubrics to accompany the Euchologion (prayer book) and guide the officiant.
They originated in the tenth century, but the earliest surviving examples date to the twelfth.
The diataxis for the Liturgy of the Presanctified Gifts attributed to Theodore of Stoudios (died 826) is not authentic.
[3] The chapters of the Taktika of Leo the Wise, a military treatise, are called diataxeis.