I am displaying html entity ✓ (a check mark: ✓) in an html document that uses iso-8859-1 for the character set.
✓
In Firefox, it display
Per http://www.w3.org, the check mark isn't part of 8859-1: http://www.w3.org/TR/html401/sgml/entities.html
It's e29c93 in UTF-8.