This is pretty much a straight copy of the zope instructions for structured text. Also this document is written in structured text so if you would like a good example just try to edit this document and you can see it.

StructuredText rules, from the ZoPe source:

"Structured text is text that uses indentation and simple symbology to indicate the structure of a document.

A structured string consists of a sequence of paragraphs separated by one or more blank lines. Each paragraph has a level which is defined as the minimum indentation of the paragraph. A paragraph is a sub-paragraph of another paragraph if the other paragraph is the last preceding paragraph that has a lower level.

Special symbology is used to indicate special constructs:

A single-line paragraph whose immediately succeeding paragraphs are lower level is treated as a header.
A paragraph that begins with a '-', '*', or 'o' is treated as an unordered list (bullet) element.
A paragraph that begins with a sequence of digits followed by a white-space character is treated as an ordered list element.
A paragraph that begins with a sequence of sequences, where each sequence is a sequence of digits or a sequence of letters followed by a period, is treated as an ordered list element.
A paragraph with a first line that contains some text, followed by some white-space and '--' is treated as a descriptive list element. The leading text is treated as the element title.
Sub-paragraphs of a paragraph that ends in the word 'example' or the word 'examples', or '::' is treated as example code and is output as is:
```
    <table border=0>
      <tr>
        <td> Foo 
    </table>
```
Text enclosed single quotes (with white-space to the left of the first quote and whitespace or puctuation to the right of the second quote) is treated as example code.
For example: '<dtml-var foo>'.
Text surrounded by '*' characters (with white-space to the left of the first '*' and whitespace or puctuation to the right of the second '*') is emphasized.
Text surrounded by '**' characters (with white-space to the left of the first '**' and whitespace or puctuation to the right of the second '**') is made strong.
Text surrounded by '_' underscore characters (with whitespace to the left and whitespace or punctuation to the right) is made underlined.
Text encloded by double quotes followed by a colon, a URL, and concluded by punctuation plus white space, or just white space, is treated as a hyper link.
For example, '"Zope":http://www.zope.org/' is interpreted as Zope

Note: This works for relative as well as absolute URLs.
Text enclosed by double quotes followed by a comma, one or more spaces, an absolute URL and concluded by punctuation plus white space, or just white space, is treated as a hyper link.
For example: '"mail me", mailto:amos@digicool.com' is interpreted as mail me
Text enclosed in brackets which consists only of letters, digits, underscores and dashes is treated as hyper links within the document.
For example: '"As demonstrated by Smith [12] this technique ..."'

Is interpreted as: "As demonstrated by Smith [12] this technique"

Together with the next rule this allows easy coding of references or end notes.
Text enclosed in brackets which is preceded by the start of a line, two periods and a space is treated as a named link. For example:
'.. [12] "Effective Techniques" Smith, Joe ...'

Is interpreted as

[12] "Effective Techniques" Smith, Joe ...

Note: see the <A NAME="12"> in the HTML source.

Together with the previous rule this allows easy coding of references or end notes.