https://thepointsguy.com/news/united-airlines-suspending-upgrade-requests/
United suspending upgrade requests ahead of PlusPoints launch - The Points Guy
Dec 3, 2019 - What you need to know about Wednesday's PlusPoints introduction.
upgrade requestsahead ofthe pointsunitedsuspending
https://www.troyhunt.com/subresource-integrity-and-upgrade-insecure-requests-are-now-supported-in-microsoft-edge/
Troy Hunt: Subresource Integrity and Upgrade-Insecure-Requests are Now Supported in Microsoft Edge