Changing The OuterHTML Of An Iframe

I discovered how to write out the inner HTML of the contents of an
Iframe; I want to know how to write out the outerHTML of the contents
of an Iframe.

frames['iframeid'].document.body.innerHTML allows me to read the inner
HTML of the contents of an iframe and also allows me to write out the
inner HTML of the contents of an iframe.

However using frames['iframeid'].document.body.innerHTML I am only able
to change, in the contents of the iframe, the code in between and
including the body tags; I am not able to change the code above the
body tag such as what is in the head section and what is in the html
tag.

The problem is, that other maneuvers that allow me to read the contents
of an iframe, do NOT allow me to write out the contents of the iframe.
These are:

frames['framid'].document.body.outerText
frames['framid'].document.body.innerText
frames['framid'].document.documentElement.outerHTML

The problem persists if the page originally loaded into the iframe
contains no code.

This looks like an unpredictable inconsistency of the type that makes
Javascript a language to be learned through experimentation. Or is
there some documentation somewhere that lists the read/write abilities
of such lines of code?