I suggest considering this from a linguistic perspective rather than a technical perspective.

For years (decades, even), KB, MB, GB, etc. were broadly used to mean 2^10, 2^20, 2^30, etc. Throughout the 80s and 90s, the only place you would likely see base-10 units was in marketing materials, such as those for storage media and modems. Mac OS exclusively used base-2 definitions well into the 21st century. Windows, as noted in the article, still does. Many Unix/POSIX tools do, as well, and this is unlikely to change.

I will spare you my full rant on the evils of linguistic prescriptivism. Suffice it to say that I am a born-again descriptivist, fully recovered from my past affliction.

From a descriptivist perspective, the only accurate way to define kilobyte, megabyte, etc. is to say that there are two common usages. This is what you will see if you look up the words in any decent dictionary. e.g.:

• https://www.dictionary.com/browse/kilobyte
• https://www.merriam-webster.com/dictionary/kilobyte
• https://en.wiktionary.org/wiki/kilobyte

I don’t recall ever seeing KiB/MiB/etc. in the 90s, although Wikipedia tells me they “were defined in 1999 by the International Electrotechnical Commission (IEC), in the IEC 60027-2 standard”.

While I wholeheartedly agree with the goal of eliminating ambiguity, I am frustrated with the half-measure of introducing unambiguous terms on one side (KiB, MiB, etc.) while failing to do the same on the other. The introduction of new terms has no bearing on the common usage of old terms. The correct thing to have done would have been to introduce two new unambiguous terms, with the goal of retiring KB/MB/etc. from common usage entirely. If we had KiB and KeB, there’d be no ambiguity. KB will always have ambiguity because that’s language, baby! regardless of any prescriptivist’s opinion on the matter.

Sadly, even that would do nothing to solve the use of common single-letter abbreviations. For example, Linux’s ls -l -h command will return sizes like 1K, 1M, 1G, referring to the base-2 definitions. Only if you specify the non-default --si flag will you receive base-10 values (again with just the first letter!). Many other standard tools have no such options and will exclusively use base-2 numbers.