Character Entities References are the way you put special letters, numbers and symbols on the web page. A character entity reference consists of an ampersand (&), followed by a pound sign (#), the number of the character entity, and finishing with a semi-colon (;). Alternately, for some characters you can put ampersand, the name of the character (but no # sign), followed by a semi-colon.
The following table shows some popular symbols :
|34||quot||“||quotation mark = APL quote|
|160||nbsp||no-break space = non-breaking space|
|174||reg||®||registered sign = registered trade mark sign|
|8226||bull||•||bullet = black small circle
bullet is NOT the same as bullet operator
Character entities or extended characters for WordPress are explained on the codex.wordpress.org website.