For example, the American Standard Code for Information Interchange (ASCII) is a 7 bit code standard for representing printable and non-printable characters.  Non-printable characters can be used in simple formatting or in managing communications protocols.  Note that this code can distinguish 128 different characters.  Because 8 bits codes are more naturally used, this ASCII code is generally extended to 8 bits.  Here are some examples:

• X”64″=’d’
• X”41″=’A’
• X”35″=’5′
• X”24″=’$’