The most common of decorative elements, a paragraphos (from which we get the word paragraph) is a horizontal stroke added near the left margin of a text. More functional than decorative, it was typically used to mark breaks in the text, lending itself to numerous uses both in literary and non-literary texts (e.g. denoting a change of speaker in a drama, marking new poems in a collection of poetry, designating a new entry in a register).
In the Pauline codex, a pragraphos is used to mark the transition from one epistle to another.