What is an XHTML Block?
• An XHTML/Data Definition Block is a reusable Block of content that provides a rich word processing (WYSIWYG) interface or Data Definition form fields for editing content. Regions which share static content across multiple pages, such as a header or footer, generally use XHTML/Data Definition Blocks. A single change to one of these blocks will propagate to all pages of the site that make use of the block.