The s10historyid() method is used internally by the S10 framework in the s10readhistory() and s10writehistory() methods to assign an ID to a class attribute, under which the input history of the attribute is managed. To determine the id, s10historyid() uses the following procedure:

1. If a constant "historyid_xxxxx" is defined in the class, where "xxxxx" is the passed name "attrname" of the attribute, then the value of the constant is returned in upper case.

2. If the attribute is defined with a reference to the Data Dictionary, and a memory ID is defined there, then this is returned in upper case.

3. If the attribute is defined with a reference to the Data Dictionary, but without a memory ID, the name of the corresponding data element is returned in upper case.

4. Otherwise, the class name, a hyphen, and the attribute name are combined to form the ID and returned in uppercase.