For more information on base-64 encoding, see:

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

Section 6.8 of RFC 2045, "MIME Part 1: Format of Internet Message Bodies," provides an official specification of base-64 encoding.

http://www.perldoc.com/perl5.6.1/lib/MIME/Base64.html

This web site contains documentation for the MIME::Base64 Perl module that provides encoding and decoding of base-64 strings.

 

Hypertext Transfer Protocol (HTTP)