A recent cross-check all of the codes on the IATI Sector codelist at http://iatistandard.org/201/codelists/Sector/ and the latest version of the DAC purpose codes published at http://www.oecd.org/dac/stats/dacandcrscodelists.htm identified 27 mismatches.
Please see this proposal in our consultations forum for more details.
This changes will be implemented after one week, assuming that there are no objections.