When I take your original text, I end up with the same message for validation because the text is not properly formatted. Basically, outside of PRE sections you have, you still have other "start of tag character" which you use for code representation. However, as that section is not within a PRE section, the parser will try to interpret that as HTML. That is normal. This is why you get the validation message. You may adjust that original message the way it should be (put all pieces of code in PRE) and resend it to me for testing. Again, if you include a less than character outside of a PRE section, that will be interpreted as HTML. When that is done, a second level of validation will kick in to assure that this is properly done. As this was not the case with the original message, you obtained that message.