Esteban Rivera

I read responses rather than page source, because most disagreements here are between what a tag claims and what a server returns. A loop, which is usually a configuration mistake. A chain through a tracking domain, which adds a hop and hands the visit to somebody else. A redirect that loses the path, sending every request to a homepage. Each is visible in the status codes along the way. The status code matters and the choice is narrower than it looks. A permanent redirect is cached by browsers with no expiry, so changing where it points later does not reach the browsers that already cached it. A temporary one is not cached. Picking the wrong one is expensive to undo. A canonical and a redirect have to agree, and when they do not the outcome is undefined in practice. This is the signal split, and it is resolved by choosing one authority and removing the other rather than by deciding which one wins. Hreflang has three rules that account for most of its failures. The values are language and optionally region. The annotations are reciprocal, so each page lists all the others including itself. And every URL listed has to be indexable, since an annotation pointing at a blocked page is discarded. I show the headers because a configuration file and a deployed header are frequently different things. Each of these is settled by removing one of the two signals rather than by deciding which one the engine prefers, because the engine is not obliged to prefer either.