International Classification For Standards - Statistics

Statistics

• The International Classification for Standards has 99 top-level divisions of which only 40 are presently used. The remaining 59 divisions are reserved for topics that are not yet known.

• There are three "official" levels in the ICS system, each holding ninety nine (99), nine hundred and ninety nine (999) and ninety nine (99) subsets, respectively.

• Each field of the ICS is designed to hold a maximum of 999 groups. The number 999 is a Kaprekar number since its square (999² = 998,001) can be split into two parts, 998 and 001, which add up to the original number again (998 + 001 = 999).

• Although any group in the ICS may contain no more than 99 "official" sub-groups, the holding capacity of the group can be expanded 99 times by using "unofficial" Level 4 subdivisions, an option that is built into the ICS. Adding Level 4 subdivisions to all sub-groups within a group increases the group's holding capacity to 9 801 subjects. Splitting this number into two parts, 98 and 01, and then adding them produces 99, the maximum number of "official" sub-groups in any given group of the ICS.

• The expanded version of the International Classification for Standards is capable of covering nearly 1 billion subjects (969,328,701 to be exact). This can be achieved without any restructuring of its numerical coding system. Since there are currently about 780 000 national standards in the world, the number of subjects that the ICS can offer for classification purposes exceeds 1 200 times the total number of documents that are available for classification.