Bi-directional text

Some languages, such as Hebrew and Arabic are written from right to left. When Latin-based text is mixed with these languages in the same sentence, the text is read in one general direction and temporarily switched to another direction when the other language is encountered.

Many computer programs fail to display bi-directional text correctly. For example, the Hebrew Tetragrammaton (יהוה) should be spelled yodh(י) heh(ה) waw(ו) heh(ה) from right to left. Some web browsers may display the Hebrew text in this article in the opposite direction.

Very few languages may be written in either direction. Such was the case with Egyptian hieroglyphics, where the signs had a distinct "head" that faced the beginning of a line and "tail" that faced the end.

Some ancient Greek inscriptions, Tuareg and Hungarian runes were written in opposite directions on alternate lines, a style called boustrophedon.