Putting special characters in the title should have no adverse effect on the layout or functionality.

Special characters in the post title have been known to cause issues with JavaScript when it is minified, especially in the admin when editing the post itself (ie. issues with metaboxes, media upload, etc.).

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Title With Special Characters ~`!@#$%^&*()-_=+{}[]/\;:'”?,.>

Putting special characters in the title should have no adverse effect on the layout or functionality. Special characters in the post title have been known to cause issues with JavaScript […]

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.