Wikipedia -> search "kibibyte" -> https://en.wikipedia.org/wiki/Kibibyte
The binary prefix kibi means 2^10, or 1024; therefore, 1 kibibyte is 1024 bytes.
The unit was established by the International Electrotechnical Commission (IEC) in 1998, has been accepted for use by all major standards organizations, and is part of the International System of Quantities.
As far as I know, this international system of quantities is the closest thing to a universal standard we have. I'm not sure if, for example, China uses it (since they like to make their own version of everything, and in many cases that's fine), but it seems widespread in the western world. I've seen the use of KiB quite a few times now, but then as a software engineer, I guess I'm more likely to see it than most.