Arabic is written from right to left in a cursive script consisting of twenty-eight letters, all representing consonants; their form varies according to position within the word, and several are distinguished only by dots. Some letters cannot be joined to the next even within a word; the space between them should be smaller than that between words, and unbreakable. A horizontal extender on the baseline is often added to a letter that would otherwise seem too close to the next. In verse it is conventional to give all lines the same visual length, so that the rhyming letter is aligned on the left throughout.
The same script, with additional letters, is or has been employed for other languages spoken by Muslims, such as Persian, Pashto, Urdu, Turkish, and Malay; these last two are now written in the Roman alphabet.
There is no standard system of transliterating Arabic.
12.2.2 Accents and punctuation
Vowel marks and other guides to pronunciation are used in editions of the Koran, in schoolbooks, and usually in editions of classical poetry; otherwise they are omitted except where a writer thinks they are needed to resolve ambiguity. Strict philological usage requires the underline in ḏ, ṯ; the under-dot in ḥ, ṣ, ḍ, ṭ, ẓ; the over-dot in ġ; the inferior semicircle in (ḫ); the háček in ǧ (often written j) and š, and the macron in ā, ī, ū (do not use the acute or circumflex instead). Less learned systems will dispense with some or all of these diacritics. There are also two independent characters, ʿayn (ʿ) and hamza (ء) (corresponding to Hebrew ʿayin and aleph) which should be used if available; if not, substitute Greek asper (‘) and lenis (’) respectively. These should be distinguished from the apostrophe, mainly found before l-, e.g. in ʿAbdu ’l-Malik; insert a hair space (see
The definite article al or ’l- (or regional variants such as el- and ul-) is joined to the noun with a hyphen: al-Islām, al-kitāb. Do not capitalize the a except at the beginning of a sentence; it should not be capitalized at the start of a quoted title.
12.2.3 Word division
In Arabic script words should not be divided even at internal spaces; if the spacing of the line would otherwise be too loose, use extenders within words. In transliteration, avoid dividing except at the hyphen following the article; if absolutely necessary, take over no more than one consonant. In loose transcription, note that dh kh sh th may represent either the single consonants strictly transliterated ḏ, ḫ, š, and ṯ respectively, or combinations of d k s t plus h. When in doubt, do not divide.