Problem
An alternative to the radix-64 conversion in S/MIME is the quoted-printable transfer encoding. The first two encoding rules are as follows:
1. General 8-bit representation: This rule is to be used when none of the other rules apply. Any character is represented by an equal sign followed by a two-digit hexadecimal representation of the octet's value. For example, the ASCII form feed, which has an 8-bit value of decimal 12, is represented by "=0C".
2. Literal representation: Any character in the range decimal 33 ("!") through decimal 126 ("∼"), except decimal 61 ("="), is represented as that ASCII character. The remaining rules deal with spaces and line feeds. Explain the differences between the intended use for the quoted-printable and base 64 encodings.