Big5 is a double-byte character set, represented in hexadecimal and stored using a two-byte encoding method, where each character is encoded with two bytes. The first byte is called the "high byte," and the second byte is called the "low byte." The high byte uses values from 0x81 to 0xFE. The low byte uses values from 0x40 to 0x7E and from 0xA1 to 0xFE.

The divisions of the Big5e encoding are organized into different ranges, with each range designated for specific types of characters or symbols:

• 0x8140-0xA0FE: This range is used for extended characters beyond the standard Big5 character set.
• 0x8740-0x875C: Another section for additional extended characters.
• 0x875D-0x877E, 0x87A1-0x87FE: This area is reserved for potential future use, allowing for further expansion of the character set.
• 0x8840-0x8DFE: This range is designated for user-defined characters, similar to the custom character areas in Big5.
• 0x8E40-0x8EFE: Another section dedicated to extended characters.
• 0xA140-A2FE: This range includes various symbols, similar to the corresponding range in the original Big5.
• 0xA340-0xA3BF: This area continues to cover various symbols, including punctuation marks.
• 0xA440-0xC5FE: This is the area for frequently used Chinese characters, similar to the original Big5, but with some extensions.
• 0xC640-0xC67E: This is an extension for frequently used characters.
• 0xC940-0xF8FE:: This range covers less frequently used characters, extending the set of Chinese characters available.
• 0xF940-0xF9D5: This continues the section for less frequently used characters.
• 0xF9D6-0xFEFE: This area includes seven additional extended characters and symbols

In the Big5 encoding system, ASCII characters are fully supported and occupy the same range as in standard ASCII, from 0x00 to 0x7F.