Proper use of cfdocument tag with html, head, body tags

What is the proper use/nesting of the cfdocument tag with the html, head, and body tags? Coldfusion seems very forgiving in this regard, but I’ll like to know the correct usage. For example, I have seen examples with the cfdocument tags both within and without the body tags and even without html/body tags. Also, in proper usage, should everything within a cfdocument tag need to be nested inside a cfdocumentsection or cfdocumentitem pair?

Thanks much,