No TB2 The guideline says Editors should use the conventional prefixes such as kilobyte KB and megabyte MB and disambiguate where necessary i e it is not mandatory to disambiguate and IEC prefixes are not to be used on Wikipedia except under the following circumstances Looking at Warren s changes where you say he has done nothing wrong on MOSNUM he has correctly removed the IEC prefixes within the scope of the guideline He obviously doesn t think disambiguation is necessary which is also within the scope of the guideline and you did say he has done nothing wrong Obviously from your comments you do think disambiguation is necessary so within the scope of the guideline you should be adding acceptable disambiguation not adding IEC prefixes back again aton