Preventing tinyMCE from auto formatting selected blocks of content

Question

Is there a way to prevent tinyMCE from auto formatting the content inside selected blocks? Something like

<!--dont-alter-->
variable range of content, text, < , ], images etc., that will not be touched by tinyMCE.
<!--end:dont:alter-->

so that when switching between editors, the content is unchanged? I have done tinyMCE plugins before, but would really appreciate some directions here.

Above functionality would be very helpful, allowing control over formatting.

Please share you wisdom. Thanks.