Does $c="&D" turn out to be anything like $crlf=""\n"?
There is nothing special about the "&" character within a PHP string literal, so in that case $c would just be set to a 2-character string of "&D". (Now, what a browser might think about it if you output that variable to the browser is a whole 'nother matter. ).
"Please give us a simple answer, so that we don't have to think, because if we think, we might find answers that don't fit the way we want the world to be."
~ Terry Pratchett in Nation