CDATA is an xml tag that tells the parser to ignore the contents of the tag. If it wasn't there, the xml parser would parse it and if it found invalid xml (such as html with missing tags), would error out. A CDATA section starts with "<![CDATA[" and ends with "]]>" (no spaces or line breaks), and cannot contain the string "]]>", therefore, nested CDATA sections are not possible.

BTW, I assume you know you can simply create a template by logging on as host, going to host->portals and using the export template option - this will export any site you choose which can then be used as the basis for other sites.

Cathal