“Census recode” refers to the Census Bureau, not the decennial census or ACS. The Census Bureau also does all data collection for the CPS (and many other surveys).
The Census Bureau sometimes aggregates variables together before making them available to researchers. For example, INCWAGE is a combination of the IPUMS variables INCLONGJ and OINCWAGE, which are the components of wage and salary income. The reason this is relevant is because the components of income are often top-coded to maintain respondent confidentiality. Each component of income is subject to top-coding. But the sum (the “Census Recode”) uses the full information available in both income components, before top-coding. Then this sum is separately top-coded. That’s why INCWAGE is not always equal to INCLONGJ + OINCWAGE.