Uncial 0189, is the oldest parchment manuscript of the New Testament.
Uncial 0189
In Christian scribal practice, nomina sacra is the abbreviation of several frequently occurring divine names or titles, especially in Greek manuscripts of the Bible. A nomen sacrum consists of two or more letters from the original word spanned by an overline.
Two nomina sacra are highlighted, ΙΥ and ΘΥ, representing of/from Jesus and of/from God (as these are genitives) respectively, in this passage from John 1 in Codex Vaticanus (B), 4th century.
Nomina sacra ΙϹ ΧϹ, from the Greek ΙΗΣΟΥΣ ΧΡΙΣΤΟΣ (Jesus Christ — the letter C on the icon being koine Greek Σ). Detail from an icon at the Troyan Monastery in Bulgaria. See complete icon
Papyrus 111 (3rd century AD), with the nomen sacrum ΙΗΥ (indicating genitive 'of Jesus', Ἰησοῦ) visible at bottom