Each listed result for a search will show some example text from the beginning of the linked page. It strips out HTML elements, but if there's any navigational text items, they will stay.
For example, each search result on ikiwiki.info shows "(title) ikiwiki/ (title) Edit RecentChanges History Preferences Discussion" at the start of its results.
A way to name some CSS ids that should be removed in search results within the ikiwiki setup file would work. Here's something similar that a friend proposed:
(bin attachment on that page is actually a .diff.)
So I was looking at this and I relized that while the search plugin used to use the format hook, and so there was no way to avoid it seeing all the gunk around the page body, it was changed a while ago for different reasons to use its own hook, postscan. So there's really no reason not to move postscan so it runs before said gunk is added to the page. (Aside from a small risk of breaking other third-party plugins that somehow use postscan.)
I've implemented that in git, and it drops the navigation elements nicely. It's perhaps less general than allowing specific divs to be skipped from search, but it seems good enough. Please thank the dragonfly guys for their work on this. done --Joey