Like most abjads, Manichaean is written from right to left and lacks vowels. Particularly, it has certain consonants that join on both sides, some that join only on the right, and some that only join on the left, and some that do not join at all, unlike the most well-known abjad, Arabic, which has only consonants that join on both sides or on the right. Manichaean has a separate sign for the conjunction "ud" (and); two dots are placed above characters to indicate abbreviations, and there are several punctuation-marks to indicate headlines, page-divisions, sentence-divisions, and others.