From http://www.w3schools.com (Copyright Refsnes Data)
The <fo:block-container> object is used to create a block-level reference-area - which often contains a different writing-mode or a different reference-orientation to rotate the content.
<fo:block-container> <!-- Contents:(block|block-container| table-and-caption|table|list-block)+ --> </fo:block-container> |
From http://www.w3schools.com (Copyright Refsnes Data)