When writing my About Me post, I considered how to include my email address. I was aware of "bots" or "spiders" which harvest email addresses from web pages.  To take a small measure for protecting myself, I decided to follow blogger Jeff Atwood’s example and use HTML coded characters when including an email address on a web page. 

Gutterbucket provides an AWESOME Escape sequence tool to convert text to either URL escape codes and HTML coded characters.  Use this tool to convert your email address to HTML coded characters.  If you use a "mailto" link, also use this tool to convert the entire "href".  For example, here is my encoded email address:

Note that these character codes tend to get overwritten by writing tools that try to “help” you. Most blogging tools will “fix” your character codes by converting them to the normal ASCII characters that are more “human readable.”  I had to bypass all tools and edit the final HTML by hand. 

Some good online "cheat sheets" I found were Creative Edge Design's Escape Codes for Commonly Requested Special Characters and Dragin Wind's exhaustive listing of HTML Coded Character Set & URL Escape Codes.

The W3C explains that The HTML Coded Character Set is based on ISO-8859-1.   

URL "escape codes" are really just a “%” plus the 2-digit ASCII Hex character code.  Wikipedia explains that,

The "escape" character (code 27), for example, was originally intended to allow sending other control characters as literals instead of invoking their meaning. This is the same meaning of "escape" encountered in URL encodings, C language strings, and other systems where certain characters have a reserved meaning.

Knowing about HTML coded characters is one of those little nuggets of web programming knowledge that you learn about over time.  Things like this are rarely needed, but essential to know about when you do need them.