> I was in the "Site Identity" menu and came across something that I couldn't find in the 900+ page manual.
> What are Breadcrumbs and what do they do?
Well, it leaves the list of (wiki) pages you visited along your tiki session..., afaik. There is also a module called breadcrumbs (there should be). And there should be a page in the Documentation explaining this Module breadcrumb, at least, plus explaining it somewhere for Site identity configuration... (Site Identity)
Could you help us improve the documentation pages, please? (see Welcome Authors )
Ask again if in doubt...