How do I use the list-style project symbol?

There are many types of project symbols, which are listed as follows:
Disc (solid dot ),
Circle (hollow circle ),
Square (solid square ),
Decimal (Arabic numerals ),
Lower-roman (lower-case roman numerals ),
Upper-roman (uppercase roman numerals ),
Lower-alpha (lowercase letters ),
Upper-alpha (uppercase letters ),
None (none ).
For example, set the project symbol of a list (ul or ol) as a square, for example:
Li {
List-style: square;
} 
In addition, list-style has some values. For example, you can use some small images as the project symbol and directly write the url ("image address") under list-style "). Note that if the left outer patch (margin-left) of a project list is zero, the list-style-position: outside (default: outside) project symbol is not displayed.