Some symbols may not show because your computer does not contain the font set and/or your browser is not set to the correct Character Encoding (utf-8 is good). Changing browser's encoding is usually done from its View Menu. Unicode browser display test: http://home.tiscali.nl/t876506/entitiesTips.html
Depending on whether language is read right-to-left or left-to-right, you may want to include that attibute: lang="ltr"/lang="rtl".
If you see squares or question marks instead of the language symbol(s) you need to make sure you have the language pack installed necessary to show the symbols.