Valheim breadcrumb - Knives

A breadcrumb key, not a real category.

`` files every Valheim page into all eleven weapon classes, because the CATEGORIES box in the right rail is built from real category membership and the whole tree is wanted there. BreadCrumbs2 takes the first rule in `MediaWiki:Breadcrumbs` whose category a page carries, so a page in all eleven can only ever resolve to whichever is listed first, and every Valheim page read "Weapons > Swords".

This category is hidden, so it never appears in that box, but `OutputPage::getCategories()` returns hidden categories too and BreadCrumbs2 calls it with no argument. A page therefore carries exactly one of these, its own, and the breadcrumb rule keyed on it matches before any visible class rule can.

Added by the page generators. Do not add it by hand and do not unhide it.