I have some code in place that uses the "Trident" string within the User Agent to determine the actual browser being used for a site that requires the use of compatibility view mode. According to everything I've read online, IE11 should present itself as "Trident/7.0". and IE 10 should present itself as "Trident/6.0". That is also consistent with what I have personally observed.
I recently had a customer that had identified an issue which we traced back to the fact that his IE11 is presenting itself as "Trident/8.0" instead of "Trident/7.0". I've modified my code to treat the "Trident/8.0" in the same manner as "Trident/7.0", but I'm really curious as to what circumstances would cause IE to present itself as "Trident/8.0".
FWIW, the customer environment is IE11 in Windows 10, which is the same environment I'm using. My PCs show the Trident string as expected, but those at my customers location do not.
Any help would be greatly appreciated.