Just found this little gem on php.net:
A note on the heredoc stuff.
If you're editing with VI/VIM and possible other syntax
editors, then using certain words is the way forward.
if you use <<<HTML
for example, then the text will be hightlighted for HTML!!
I just found this out and used sed to alter all EOF to
tags.., so use HTML
too.. There might
be one for Text/css too?