Special Characters:

Cascade stores data in XML format.  This means that reserved characters like ampersand(&), apostrophes('), and <> or quotes need to be encoded in special ways to show up correctly in titles and not cause weird upside-down question marks to render in your content.

Within the WYSIWYG regions in order to enter special characters you can always use the upper left Omega or upside down horseshoe button on the toolbar.

If you are entering information into a text field or text area like a Title or Display Name you'll need to use the proper xml utf-8 character encoding.  

Also if you are entering a link in that has ampersand or other characters you'll need to url-encode the ampersands as %26

Here are some common encodings: