Knowing where the comments start could be solved with a highlighted scrollbar. Such as are common in programming IDE's, Eclipse for example puts one color where

Knowing where the comments start could be solved with a highlighted scrollbar. Such as are common in programming IDE's, Eclipse for example puts one color where every TODO is and another color for mark occurances etc. Just put a colored marking or a small arrow even at the scrollbar-position where the comments start. Or why not put one at each heading of the page. Implementing this accurately on a web page with js is a bit tricky since most browsers display progress bars differently. The biggest problem is if it has tiny arrows at both ends or only on one side. You will get a few pixels off if you try to match the native scroll bar. Another option is to put a second scroll bar next to the native one that is annotated, I've found this to be the most reliable option. An API from the browser to get help from the native scroll bar, or to enhance the native scroll bar would be great.