From http://www.w3schools.com (Copyright Refsnes Data)

XSL-FO float Object

Definition and Usage

The <fo:float> object is typically used to position an image in a separate area at the beginning of a page OR to position an image to one side, with the content flowing along-side of the image.

It is an error if <fo:float> is a descendant of a flow that is not assigned to a region-body.

It is also an error if <fo:float> is a descendant of an fo:block-container that generates an absolutely positioned area.

<fo:float> cannot have an <fo:float>, <fo:footnote> or <fo:marker> as a descendant.

Syntax

<fo:float>
  <!--
	Contents:(block|block-container|
	table-and-caption|table|
	list-block)+
  -->
</fo:float>

Properties

From http://www.w3schools.com (Copyright Refsnes Data)