Bidirectional describes either

  • Bidirectional (writing system): "A writing system in which text is generally flush right, and most characters are written from right to left, but some text is written left-to-right as well. Arabic and Hebrew are the only bidirectional writing systems in current use." (MultiLingual)
  • Bidirectional text ("bidi"): "A mixture of characters within a text where some are read from left to right and others from right to left. Bidirectional or bidi refers to an application that allows for this variance." (MultiLingual)

Many computer programs fail to display bi-directional text correctly.