Does a code in parenthesis in the ACS OCC codes table indicate that the occupation was included in the broader category in previous year surveys, but moved to a new category with updates to the classification system? Is there some documentation that defines the meaning of the parentheses in this table?
The parentheses are meant to signal that the code is also represented somewhere else in that column of the table, for when codes were split or combined in such a way that they had to be separated on the table. This is referenced in the table description here: “This tables notes changes in the coding scheme over time by referencing which new categories are included in the prior code” but I agree that we should be more clear about the meaning of the parentheses. I will pass along this message to the IPUMS-USA team and we will add more descriptive text to the table in the near future.
I hope this helps.