There’s a change by change summary of the December 2017 DAC codelist updates here: https://github.com/datasets/dac-crs-codes/pull/40
The diff is here (so you can see exactly what changed): https://github.com/datasets/dac-crs-codes/pull/40/files
This is all consistent with the self-declared changes on the ‘web link’ page of the XLS file.