addition to the accent marks, every word-initial vowel must carry either of two so-called "breathing marks": the rough breathing (ἁ), marking an /h/ sound The Greek alphabet has been used to write the Greek language since the late 9th or early 8th century BC. It was derived from the earlier Phoenician alphabet, and is the earliest known alphabetic script to systematically write vowels as well as consonants. In Archaic and early Classical times, the Greek alphabet existed in many local variants, but, by the end of the 4th century BC, the Ionic-based In the polytonic orthography traditionally used for ancient Greek and katharevousa, the stressed vowel of each word carries one of three accent marks: either the acute accent (ά), the grave accent (ὰ), or the circumflex accent (α̃ or α̑). These signs were originally designed to mark different forms of the phonological pitch accent in Ancient Greek. By the time their use became conventional and obligatory in Greek writing, in late antiquity, pitch accent was evolving into a single stress accent, and thus the three signs have not corresponded to a phonological distinction in actual speech ever since. In addition to the accent marks, every word-initial vowel must carry either of two so-called "breathing marks": the rough breathing (ἁ), marking an /h/ sound at the beginning of a word, or the smooth breathing (ἀ), marking its absence.… There are many different methods of rendering Greek text or Greek names in the Latin script. The form in which classical Greek names are conventionally rendered in English goes back to the way Greek loanwords were incorporated into Latin in antiquity. In this system, ⟨κ⟩ is replaced with ⟨c⟩, the diphthongs ⟨αι⟩ and ⟨οι⟩ are rendered as ⟨ae⟩ and ⟨oe⟩ (or ⟨æ,œ⟩); and ⟨ει⟩ and ⟨ου⟩ are simplified to ⟨i⟩ and ⟨u⟩. Smooth breathing marks are usually ignored and rough breathing marks are usually rendered as the letter ⟨h⟩. In modern scholarly transliteration of Ancient Greek, ⟨κ⟩ will usually be rendered as ⟨k⟩, and the vowel combinations ⟨αι, οι, ει, ου⟩ as ⟨ai, oi, ei, ou⟩. The letters ⟨θ⟩ and ⟨φ⟩ are generally rendered as ⟨th⟩ and ⟨ph⟩; ⟨χ⟩ as either ⟨ch⟩ or ⟨kh⟩; and word-initial ⟨ρ⟩ as ⟨rh⟩. Transcription conventions for Modern Greek differ widely, depending on their purpose, on how close they stay to the conventional letter correspondences of Ancient Greek-based transcription systems, and to what degree they attempt either an exact letter-by-letter transliteration or rather a phonetically based transcription. Standardized formal transcription systems have been defined by the International Organization for Standardization (as ISO 843), by the United Nations Group of Experts on Geographical Names, by the Library of Congress, and others.