Unicode has the explicit aim of transcending the limitations of traditional character encodings, such as those defined by the ISO 8859 standard, which find wide usage in various countries of the world but remain largely incompatible with each other. Many traditional character encodings share a common problem in that they allow bilingual computer processing (usually using Latin characters and the local script), but not multilingual computer processing (computer processing of arbitrary scripts mixed with each other).

Answer this question, if possible (if impossible, reply "unanswerable"): What is the major limitation of traditional character encodings?
wide usage in various countries of the world but remain largely incompatible with each other