Here's the code I used to embed the PDF file:<iframe src="http://docs.google.com/gview?url=http://infolab.stanford.edu/pub/papers/google.pdf&embedded=true" style="width:600px; height:500px;" frameborder="0"></iframe>
This is a annotation/hightlight vs comment selected text test.
See discussion here
NB: In comments the HTML code gets rendered! =D
Which means you can use HTML in comments! =D