ISO 4217 "ruble". In addition to codes for most active national currencies ISO 4217 provides codes for "supranational" currencies, procedural purposes, and several things which are "similar to" currencies: The use of an initial letter "X" for these purposes is facilitated by the ISO 3166 rule that no official country code beginning with X will ever be assigned. Because of this rule ISO 4217 can use X codes without risk of clashing with a future country code. ISO 3166 country codes beginning with "X" are used for private custom use (reserved), never for official codes. For instance, the ISO 3166-based NATO country
ISO/IEC 27000-series credits Donn B. Parker as having the "original idea of establishing a set of information security controls", and with producing a document containing a "collection of around a hundred baseline controls" by the late 1980s for "the I-4 Information Security circle which he conceived and founded." The published ISO27K standards related to "information technology - security techniques" are: ISO/IEC 27000-series The ISO/IEC 27000-series (also known as the 'ISMS Family of Standards' or 'ISO27K' for short) comprises information security standards published jointly by the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC). The series provides best practice recommendations