RKM code
The RKM code is a notation for the specification of resistors and capacitors, defined since 1952 by the International Electrotechnical Commission (IEC) in its standard IEC 60062 (formerly IEC 62). It is also referred to as "letter and numeral code for resistance and capacitance values and tolerances", "letter and digit code for resistance and capacitance values and tolerances", or informally as "R notation".