== Terminology == 

 This issue has cropped up before (search archives) but it has never been fully resolved, so bringing it up again. There are two sets of prefixes here, going by "mention": the kilo/mega/giga set, and the kibi/mebi/gibi set. And there are at least three sets of prefixes, going by "use": the kilo/mega/giga set used in the decimal sense, the kilo/mega/giga set used in the binary sense, and the kibi/mebi/gibi set used in the binary sense. (There are also others, like the kilo/mega/giga set used in the approximation sense, where 32K+32K=65K, but probably less important.) So we need to decide on names for all of these, and be consistent throughout the article. It currently uses "SI prefixes" for the first of the three, "traditional binary prefixes" for the second, and "IEC prefixes" for the third. (The latter two are somewhat of a misnomer, because "traditional" depends on what area (and concomitant tradition) one is speaking about, and "IEC" does not reflect the fact that the IEC was neither the first to come up with the prefixes nor the only standard to have embraced them.)  

 It would be good if someone came up with better names. At any rate, though, calling the second one "common practice prefixes" is misleading, because it's the common practice in some areas (computer memory) but not in others (speeds, drives). As someone says "Everyone knows that 1MB is 1024KB, unless you’re talking about DVDs, or reading manufacturer specs for a hard drive, and that’s just the hard drive manufacturers being stupid. Everyone knows that ‘K’ on a computer means 1024; except for speeds, where it means 1000, except for file download speeds where it means 1024, except when it’s the speed of your modem, when it’s 1000. Everyone knows that. What, are you stupid?"