To separate presentation from content, what code should be removed up and what should not?
Start by removing presentational code entangled in the HTML files but keep your information structure, such as navigation and header levels.
Example of presentational code: Nested <table>'s used for positioning only; <img>, <p> or <br> tags used for spacing only; <font> tags used for color or typeface changes — they can all be removed without altering your actual message, right?