"Viewing the source i noticed the use of decimal encoding of the ASCII value for the angle bracket, the format being "ampersand, pound, decimal value 60)."

You can also use "ampersand, 'l', 't'" for < (less than) and "ampersand, 'g', 't'" for > (greater than)

"I also noted that if i used "preview" to view my post, the encoding (in my Message Text) was automatically changed to the angle bracket so i had to post without review."

Same applies - see Rob's workaround.