2045 RFC - Base64 Encoding for Binary attachments

http://www.ietf.org/rfc/rfc2045.txt

I came across the above link while I was reading about XML-RPC. As XML prohibits any character with an ordinal value lower than that of the space character( 32), commonly called control characters. Although, binary items, such as binary files, may contain these characters. The solution is to use an ASCII-based encoding of the binary object, and XML-RPC uses base-64 encoding.