British Standards Institution document DISC PD2000-1	MST TRANSLATION
Rule 2 2.1 This rule is sometimes known as the date integrity. 2.2 This rule means that all equipment and products must calculate, manipulate and represent dates correctly for the purposes for which they were intended. 2.3 The meaning of functionality includes both processes and the results of those processes. 2.4 If desired, a reference point for date values and calculations may be added by organisations; e.g. as defined by the Gregorian calendar. 2.5 No equipment or product shall use particular date values for special meanings; e.g. "99" to signify "no end value" or "end of file" or "00" to mean "not applicable" or "beginning of file".	RULE 2: ALL YOUR COMPUTERS MUST HANDLE ANY DATE CORRECTLY AND UNAMBIGUOUSLY
Rule 3 3.1 This rule is sometimes known as explicit/implicit century 3.2 It covers two general approaches: (a) explicit representation of the year in date: e.g. by using four digits or by including a century indicator. In this case, a reference may be inserted ( e.g. 4-digit years as allowed by ISO standard 8601:1988) and it may be necessary to allow for exceptions where domain-specific standards (e.g. standards relating to Electronic Data Interchange, Automatic Teller Machines or Bankers Automated Clearing Services) should have precedence. (b) the use of inferencing rules: e.g. two-digit years with a value greater than 50 imply 19xx, those with a value equal to or less than 50 imply 20xx. Rules for century inferencing as a whole must apply to all contexts in which the date is used, although different inferencing rules may apply to different date sets.	RULE 3: WHERE POSSIBLE, USE 4 DIGITS TO REPRESENT YEARS. IF THIS IS NOT POSSIBLE, REFER TO DATES IN A WAY THAT CANNOT BE MISUNDERSTOOD.

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