Part of the challenge of localizing a writing system may depend on whether the characters of the writing system are single- or multi-byte characters. That is, some of the issues that may need to be considered are whether the format is the 8-bit character format used for the ASCII environment of European and/or English-speaking locales or whether the format is multi-byte, wherein a single character, European or Asian, is represented by one, two or more bytes in a code set.

To further complicate matters, a writing system may be considered "simple": e.g., Roman, Greek, or Cyrillic. Alternatively, it might be large but "non-complex." The Japanese, PRC Chinese, Taiwanese, and Korean systems, with approximately 6900, 7500, 13,800 and 8200 official characters, respectively, are included in this large, non-complex classification. Hebrew, Arabic and Southeast Asian languages are considered complex because although the actual character sets may be relatively small, the writing systems are bidirectional and/or contextual. For instance, although Hebrew is a right-to-left writing system, numbers are written from left-to-right. So a sentence containing numbers will have script written in both directions.