Putting special characters in the title should have no adverse effect on the layout or functionality.
The post title renders the word "with" in italics and the word "markup" in bold.
The post title markup should be removed from the browser window / tab.
Title should not overflow the content area
A few things to check for:
Non-breaking text in the title, content, and comments should have no adverse effects on layout or functionality.
Check the browser window / tab title.
This post has no title, but it still must link to the single post view somehow.
This is typically done by placing the permalink on the post date.