User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9a1) Gecko/20051224 Firefox/1.6a1 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9a1) Gecko/20051224 Firefox/1.6a1 NOTE: I belive this should be filed in layout, but that option is unavailable?? The problem exists when a comment has the characters '--' in it. For example, <!-- Yk2--B_345 --> My guess from perusing the spec is that this is an attempt to work around scripts and CSS embedded in HTML comments (illegal in XHTML strict) by saying "if -- exists in the block, it is not a comment"? If that is indeed the case may I suggest checking to make sure there is a <script> or <style> block in the comment before deciding to render this content. Removing the doctype eliminates the problem. Tested on ffox 1.6a as of 12/24/2005 and ffox 1.5 on winXP. Reproducible: Always Steps to Reproduce: 1. Make an HTML comment with the characters -- in it 2. Set doctype to XHTML/Strict 3. Render. Actual Results: Full comment text including start and end of comment tags (<!-- and -->) is displayed. Expected Results: Hide the comment.

Would have been clearer if that first sentence said: The problem exists when a comment has the characters '--' in it AND doctype is XHTML strict. As it is now you don't realize it's related to XHTML strict parsing until much later. Sorry for the confusion.

-- inside a comment is invalid ! See http://www.w3.org/TR/html4/intro/sgmltut.html#h-3.2.4 *** This bug has been marked as a duplicate of 214476 ***