It looks like Google.com and Sitemaps.org host the same exact copies of the Sitemaps.org information. Is this a classic no-no when it comes to duplicate content? Jamie Alberico posted about this on Twitter and yea, it seems to be the case.
Google does own the domain, sitemaps.org but it also seems Google is the only one maintaining the content?
I don’t know if this is still the case, it used to be that the responsibility for keeping the site up was shared and rotated between some of the initial companies involved. They likely all have a version of the site hosted somewhere because of that.
— ? John ? (@JohnMu) September 29, 2020
I guess Google needs to lend Sitemaps.org an SEO to add some canonical tags?
I suspect this is super old but I never noticed it.
Forum discussion at Twitter.