Quoted content can be placed between [quote] tags in order to be displayed as an indented quote. Every [quote] tag must have a corresponding [/quote] tag. For example:

[quote]This is a simple quote.[/quote]

Additionally, there is an optional attribute which allows quotes to specify the original author.

[quote=Mr. Drupal]This is a quote with an attribution line.[/quote]

Finally, multiple [quote] tags can be nested within one another. Just remember that every [quote] tag must have a corresponding [/quote] tag.

[quote]I think she says it best...
[quote=Ms. Quotation]This is a quote nested within another quote.[/quote]
but you can't argue with
[quote=Ms. Reply]The more quotes, the merrier.
Just don't get too carried away.[/quote]
And I have nothing more to say.[/quote]