The main exception to this was Opera back when it had its own engine, which did use Opera at the start of its fairly clean default UA string. Then when they reached version 10 they had to make the primary version 9 with a second real version later in the string as sites couldn’t cope with two digit version numbers…

There's a field in the Volume Boot Record of disc volumes, in the PC compatible world, that was supposed to be the name of the OEM whose software formatted the volume. It was (and is) a few bytes of identifying human-readable text. Operating systems ended up doing string comparisons and parsing numbers, and breaking in odd ways, including not even recognizing their own handiwork, when operating system vendors did not use the name of the first vendor.

* https://jdebp.uk/FGA/volume-boot-block-oem-name-field.html

It has probably been long enough since MS-DOS 3.3 and in turn the Browser Wars that someone is right now failing to learn from history and making this mistake anew, yet again, somewhere.

Because the reason it is the way it is in the first place is compatibility with sites that are doing things objectively wrong already, which makes it really hard to get them to change.

The problem is that poorly designed systems limit access or disable features based on a user-agent allowlist, which is never the right answer. There is no right way to do it because it's always wrong, but people choose to do it anyways.

I'm personally a fan of treating broken sites as broken, but I understand that realistically any "alternative" browser has to deal with all the broken sites designed for whatever came before it because otherwise most normal users won't consider switching.

If I were made King of the Internet for a day and able to enforce any changes I wanted on everyone, all the major browsers would have to change their user-agent string to something totally unique on the same day, intentionally breaking any sites that are doing it wrong for everyone so the broken sites are forced to fix their own nonsense. That'd come maybe two or three decrees down the line from "All ISPs are required to provide a globally routable IPv6 block in accordance with RFC 6177, providing only CGN IPv4 is a capital offense".

Now Apple has the year in the OS version we'll have people wondering in a few years what happened to iOS 19-25.

Windows reports its version numbers as a series of integers or by bools from helper functions, not as a string, and if there was any code that did you could easily work around it by having it report "Windows Nine" or "Windows v9" or whatever.

https://learn.microsoft.com/en-us/windows/win32/api/sysinfoa...

https://learn.microsoft.com/en-us/windows/win32/sysinfo/vers...