This International Standard specifies rules for the simplified representation, dimensioning and tolerancing of
holes, counterbores, internal threads and chamfers on drawings.
Where there could be misinterpretation using simplified representation, the complete representation and
dimensioning by cuts, sections or elements on a larger scale apply, according to ISO 128-30, ISO 128-34,
ISO 128-40, ISO 128-44, ISO 128-50, ISO 129-1 and ISO 406.