In a right-to-left, top-to-bottomscript, writing starts from the right of the page and continues to the left. This can be contrasted against left-to-right writing systems, where writing starts from the left of the page and continues to the right. Arabic, Hebrew, Pashto, Persian, Urdu, and Sindhi are the most widespread RTL writing systems in modern times. Right-to-left can also refer to scripts such as Chinese, Japanese, and Korean, though in modern times they are also commonly written. Books designed for predominately TBRL vertical text open in the same direction as those for RTL horizontal text: the spine is on the right and pages are numbered from right-to-left.
Uses
, Hebrew, Persian, and Urdu are the most widespread RTL writing systems in modern times. As usage of the Arabic script spread, the repertoire of 28 characters used to write the Arabic language was supplemented to accommodate the sounds of many other languages such as Persian, Pashto, etc. While the Hebrew alphabet is used to write the Hebrew language, it is also used to write other Jewish languages such as Yiddish. Syriac and Mandaean scripts are derived from Aramaic and are written RTL. Samaritan is similar, but developed from Proto-Hebrew rather than Aramaic. Many other ancient and historic scripts derived from Aramaic inherited its right-to-left direction. Several languages have both Arabic RTL and non-Arabic LTR writing systems. For example, Sindhi is commonly written in Arabic and Devanagari scripts, and a number of others have been used. Kurdish may be written in Arabic, Latin, Cyrillic or Armenian script. Thaana appeared around 1600 CE. Most modern scripts are LTR, but N'Ko, Mende Kikakui, Adlam and Hanifi Rohingya were created in modern times and are RTL. Ancient examples of text using alphabets such as Phoenician, Greek, or Old Italic may exist variously in left-to-right, right-to-left, or boustrophedon order; so it is not always possible to classify some ancient writing systems as purely RTL or LTR.
Computing support
Right-to-left, top-to-bottom text is supported in common consumer software. Often this support must be explicitly enabled. Right-to-left text can be mixed with left-to-right text in bi-directional text.
Sogdian, and Manichaean – derived from Syriac. Sogdian eventually rotated from RTL to top-to-bottom, giving rise to the Old Uyghur, Mongolian, and Manchu vertical scripts.
Old Italic alphabets – Early Etruscan was RTL but LTR examples later became more common. Umbrian, Oscan, and Faliscan were written right-to-left. Unicode treats Old Italic as left-to-right, to match modern usage. Some texts are boustrophedon
Lydian alphabet – ancient; some texts are left-to-right or boustrophedon.
