Documentation unclear

I was stumped looking at "Select node types to include in image captioning:"

My first thought was that I should select 'image' nodes.
Reading the source I see that it's a flag on whether images embedded in the pages of that node type may be processed for captioning.
Perhaps a line of description there could help.

I'm looking to extend captioning with jquery - to make the text show up dynamically on mouseover in my gallery pages, so I thought I'd see if I could work with this. I'm still not sure.

Isn't this task you are currently doing with jquery much better to do in a filter, seeing as it's just text manipulation? I've just written one like that to add lightbox effects to my inlined images... to work alongside a wysiwyg.