This example explains how to link an additional pull quote to an article, so it contains multiple pull quotes. The same applies on any other article elements not marked as 'single' in the schema.
In the default schema, the pull quote element is marked as "linkable to multiple frames" (see typeLink for details). This means if you add an additional pull quote by means of the same procedure you used to add the first pull quote, Fred won't create a new pull quote element, but will link the first pull quote element to the new frame.
The way to add the additional pull quote is to open the article palette (press A), right-click the root of the article, and then select Insert new element.
When prompted, confirm you want to check-out the article, and then select the Pull quote element and press OK.
Right-click the article root in the palette, and then select Save Article and Modified Elements.
Now, add a pullquote frame, and then select the new pullquote:
Select the body frames inside which you want to add a pull quote. Eg., if you want the pull quote to be over one column, select the body frame you want. Click the Add pull quote icon. When prompted for the format and number of lines, select what you want. The pull quote frame is placed above body frame and wraps its shapes.