Thanks for bringing the conflicting information on the forum to our attention–we will work to find and provide updates on conflicting posts.
The Census Bureau’s 2010 occupation coding scheme is the basis for OCC2010.
However, there are some cases where OCC2010 collapses detail added in the 2010 coding scheme to facilitate comparability over time (often, but not exclusively, using a 2002 code that was broken into multiple occupations under the 2010 scheme). The value labels for some OCC2010 codes may not correspond to the 2010 occupation code labels, but do reflect the occupational composition of the code. For example, the OCC2010 combines the original OCC codes of 4700 (OCC label "First-Line Supervisors of Non-Retail Sales Workers) and 4710 (OCC label "First-Line Supervisors of Retail Sales Workers); OCC2010 assigns both to the code of 4700 but the label has been updated to “First-Line Supervisors of Sales Workers” (removing the retail versus non-retail specification). Note that if you do not use the IPUMS code labels this aggregation could be problematic.
In light of the updated 2018 occupation codes, we will be reassessing if some codes currently collapsed in OCC2010 should be made available without aggregation to similar occupations. We will also update the documentation for OCC2010 to clearly note where we have made decisions to collapse codes.
I hope this helps. Please let me know if you have further questions.