Companion post to this one which demonstrates the issue of using "Hidden " (including the quotation marks and space at the end) as a subject line in a Dreamwidth post. As of right now, at the time of this post, the subject line on this post should not be visible. If, at some point in the future, the subject line actually shows up without a problem, then it means that this issue was fixed, after the creation of this post.
Issue originally encountered here, for reference.
Issue originally encountered here, for reference.