A way of narrowing the results (48 passages, no note) of the search by one property of the entities: their type, their source, their domain, their application, or whether a note defines them. The results page lists every value the site knows with the number of results carrying it, counted in the browser over the current query; the selected values combine, a value nothing would come of stays listed at zero rather than vanishing, and the choice travels in the address of the page so that a search (note: Search) can be sent (3 passages, no note) as a link (note: Link).
Not to be confused with
The filter of the mentions panel (note: Mentions panel), which narrows (3 passages, no note) the mentions (note: Mention) of one page by their text and has no count.