I believe it's just for the indent tags, since it shifts everything over and the [sub] and [sup] minimize and either move it down, or up an increment or two, but for [i]sub[/i] and [i]sup[/i] tags, I always use them as the last tag, as in it comes after all the other tags. You can also use them to shrink the Headers options and they also work on images as well, but it's a bitch to do. I recommend use the sub and sup tags for text only in that regard, unless you use breaker/border .png images like I do, you can squeeze the text and image together to make it look like they were created that way, similar to how I did in my Relationship Sheet for Jer.