8.5. Safari

Some of these solutions might apply to browsers other than Safari, although the specific directions (like how to set preferences) would be different.

8.5.1. Special characters, such as accented letters, turn into other characters or question marks in diamonds

This is caused by encoding mismatches (encoding is how characters are represented by numbers that the computer needs). The Web page and your browser have to use the same encoding system so that what started out as an é or a bullet on the creator's end shows up as that é or bullet on your end. When the encodings don't match, your Web pages can display gibberish.