5.3. SCTID Constraints

The permissible value for theare limited by the following rules:

Only positive integer values that are greater than 10⁵ and less than 10¹⁸ are permitted.
The only valid string renderings of the identifier value are String (data type) of decimal digits (0-9), commencing with a non zero digit.
The second and third digits from the right hand end of the string rendering of the identifier must match one of the
The rightmost digit of the string rendering is aand must match the value calculated using the specified

As a result of these rules, many 64-bit integers are not validThe value limitations enable any validto be stored in either a signed or unsigned 64-bit integer.
The rules also ensure that an SCTID (data type) can be distinguished from code from one of the antecedent code systems(which are 4 or 5 characters in length) and legacyfromand it predecessors (which always start with a letter).
identifiers areidentical to those used inbut in some cases will now refer toIn these cases, data in the 900000000000489007 |Concept inactivation indicator reference set| and 900000000000522004 |Historical association reference set| can be used to find the identifier of the closest equivalent